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第三章TEM样品制备技术ppt课件

第三章TEM样品制备技术ppt课件
电子穿透样品的厚度与电子的能量有关: 100kV---100nm; 200kV---200nm;
高分辨原子像要求的样品厚度应在10nm以下,甚至5nm以下。
经营者提供商品或者服务有欺诈行为 的,应 当按照 消费者 的要求 增加赔 偿其受 到的损 失,增 加赔偿 的金额 为消费 者购买 商品的 价款或 接受服 务的费 用
经营者提供商品或者服务有欺诈行为 的,应 当按照 消费者 的要求 增加赔 偿其受 到的损 失,增 加赔偿 的金额 为消费 者购买 商品的 价款或 接受服 务的费 用
一、质厚衬度
衬度:眼睛能观察到的或者其它媒介能记录到 的光强度或感光度的差异; 质厚衬度就是样品中不同部位由于原子序数不 同或者密度不同、样品厚度不同,入射电子被散 射后能通过物镜光阑参与成像的电子数量不同, 从而在图像上体现出的强度的差别。
经营者提供商品或者服务有欺诈行为 的,应 当按照 消费者 的要求 增加赔 偿其受 到的损 失,增 加赔偿 的金额 为消费 者购买 商品的 价款或 接受服 务的费 用
常用电解减薄液
序号
电解液成分与配比
适用材料
1
乙醇(80ml),冰醋酸(80ml), 高氯酸(15ml),甘油(10ml)
高温合金,耐
热钢,铝及其 合金。
的结构和工作原理,而且应该掌握样品制备的基本技术。
电镜样品制备的特点
电镜样品制备属于破坏性分析。 花费时间很多,有时甚至超过整个研究工作量的一半以上。 制样技术随电镜技术的发展而发展的。 制样技术分两大类:生物样品制备、材料科学样品制备。本文只
讲述材料科学中的制样技术,这些试样大多是有一定硬度的固态 物质。 制备成薄膜,膜厚取决于电子束的穿透能力和分析要求。
支持膜分散粉末法是 常用的制样方法。

第1章02 TEM样品制备、应用

第1章02 TEM样品制备、应用
24
薄膜样品制备方法要求: 薄膜样品制备方法要求:
(1)不引起材料组织的变化; )不引起材料组织的变化; (2)足够薄,否则将引起薄膜内不同层次图象的重迭, )足够薄,否则将引起薄膜内不同层次图象的重迭, 干扰分析; 干扰分析; (3)薄膜应具有一定的强度,具有较大面积的透明区域; )薄膜应具有一定的强度,具有较大面积的透明区域; (4)制备过程应易于控制,有一定的重复性,可靠性。 )制备过程应易于控制,有一定的重复性,可靠性。
21
22
a-样品制备示意图 样品制备示意图
b-45钢900℃水淬,600℃ 回火1h,6000×
23
晶体薄膜制备法
复型法,分辨本领较低, 复型法,分辨本领较低,不能充分发挥透射电镜高分 辨率( 辨率(0.2~0.3nm)的效能;复型(除萃取复型外)只能 )的效能;复型(除萃取复型外) 观察样品表面的形貌,而不能揭示晶体内部组织的结构。 观察样品表面的形貌,而不能揭示晶体内部组织的结构。 通过薄膜样品的制备方法, 通过薄膜样品的制备方法,可以在电镜下直接观察分 析以晶体试样本身制成的薄膜样品,从而可使透射电镜得 析以晶体试样本身制成的薄膜样品, 以充分发挥它极高分辨本领的特长, 以充分发挥它极高分辨本领的特长,并可利用电子衍射效 应来成象,不仅能显示试样内部十分细小的组织形貌衬度, 应来成象,不仅能显示试样内部十分细小的组织形貌衬度, 而且可以获得许多与样品晶体结构如点阵类型,位向关系、 而且可以获得许多与样品晶体结构如点阵类型,位向关系、 缺陷组态等有关的信息。 缺陷组态等有关的信息。
3
支持膜材料必须具备下列条件: 支持膜材料必须具备下列条件: 本身没有结构,对电子束的吸收不大; ① 本身没有结构,对电子束的吸收不大; 本身颗粒度要小,以提高样品分辨率; ② 本身颗粒度要小,以提高样品分辨率; 本身有一定的力学强度和刚度, ③ 本身有一定的力学强度和刚度,能忍受电子束的 照射而不致畸变或破裂。 照射而不致畸变或破裂。 常用的支持膜材料有:火棉胶、 常用的支持膜材料有:火棉胶、聚醋酸甲基乙烯 酯、碳、氧化铝等。 氧化铝等

《TEM操作培训》课件

《TEM操作培训》课件

04 TEM操作注意事项
CHAPTER
安全注意事项
确保操作区域安全
01
在操作TEM(透射电子显微镜)时,应确保操作区域没有障碍
物,避免人员和物品与设备发生碰撞。
遵守安全操作规程
02
在进行TEM操作前,应仔细阅读并遵守设备的安全操作规程,
确保正确使用设备。
避免高电压和高电流
03
在操作过程中,应避免高电压和高电流对人员和设备造成伤害
数据存储与备份
及时存储数据
在观察和记录TEM图像时,应及时将数据存储在稳定的存储介 质上,如硬盘或云端存储。
定期备份数据
为防止数据丢失,应定期备份存储的数据,并确保备份数据的可 读性和可用性。
加密存储和备份数据
为了保护数据的机密性和完整性,应对存储和备份的数据进行加 密处理,以确保数据的安全性。
05 实践操作与案例分析
,特别是在调节电压和电流时。
设备维护与保养
定期检查设备状态
在使用TEM后,应定期检查设备 的状态,包括电子显微镜的镜头
、真空系统和照明系统等。
清洁设备表面
应定期清洁设备的表面,保持设备 的清洁度,避免灰尘和污垢对设备 造成损害。
定期更换消耗品
在操作过程中,某些部件会逐渐磨 损或消耗,如灯丝和真空过滤器等 ,应定期更换以确保设备的正常运 行。
样品制备方法
总结词
样品的制备是TEM操作中的关键步骤,直接影响观察结果的准确性和可靠性。
详细描述
样品制备是TEM操作中的重要环节,需要采用一系列精细的制样技术。这包括将样品切成薄片、进行 减薄处理、以及在特定环境中进行保护和固定等步骤。制备良好的样品能够提供更清晰、更准确的观 察结果,并有助于提高实验的可重复性。

TEM制样技术(共33张PPT)

TEM制样技术(共33张PPT)

超薄碳膜
超薄碳膜,也是支持膜的一种,是在微栅的基础上,叠加了一层很薄的碳膜,一般为3-5nm 。这层超薄碳膜的目的,是用薄碳膜把微孔挡住。这主要是针对那些分散性很好的纳米材料 ,如:10nm以下的样品,分散性极好,如果用微栅就有可能从微孔中漏出,如果在微栅孔边 3超缘m薄m,碳薄膜由片,,机于也械是膜磨支光厚持;膜可的能一种会,影是在响微栅观的察基础。上所,叠以加,了一用层超很薄薄的碳碳膜膜,一,般就为3会-5n得m。到很好的效果
Dimple grinder JCP200磁控溅射镀膜仪 金属薄膜样品的制备方法
Resin embedding
Rough polishing 由于电子束的穿透能力有限,为了得到较大的磁场强度,物镜的上下极靴距离做得很短,透射电镜样品室很小,样品台所能放下的样品一般是 Φ3mm,厚度0.
Specimen cutting
Specimen cutting
Precision cutting machine
Resin embedding
Cutting
Rough polishing dia. punching
Precision polishing
Disk punch / Supersonic disk cutter Dia lap polishing system
5、认识并学会使用样品制备的常用工具与耗材。
透射电镜制样用工具类
一、载网类 (纯碳膜、超薄碳膜、微栅、铜网、铜环)—参考网站:新兴百瑞
微栅类:微栅是支持膜的一个品种,在制作支持膜时,特意在膜上制作的微孔,所以也叫“微 栅支持膜”,它也是经过喷碳的支持膜,一般膜厚度为15-20nm。它主要是为了能够使样 品搭载在支持膜微孔的边缘,以便使样品“无膜”观察。无膜的目的主要是为了提高图像衬 度。所以,观察管状、棒状、纳米团聚物等,常用“微栅”支持膜,效果很好。特别是观察 这些样品的高分辨像时,更是最佳的选择;碳膜厚度可根据用户使用情况特制;如果样品 颗粒尺寸小于10nm,请用超薄碳膜。

TEM制样PPT-2

TEM制样PPT-2

二截面样品制备
1.选样品
2.样品的清洗处理
3.对粘样品
1.选样品
低倍立体显微镜下选样品,表面平坦,没有损伤,不选样品的边缘。

用线锯或解理刀把样品切成小块,样品的对角线不超过3mm即
可。

2.清洁处理
无水乙醇------丙酮------两次超声清洗,每次2至3分钟。

3.对粘样品
清洗后的样品从丙酮里捞出来,自然干燥后,在样品的生长表面里涂上少量胶(M-
Bond610),将两块样品的生长面,面对面粘在一起,快速放入夹具中加压,固定,在130℃左右的加热炉上固化两小时以上,冷却后取出,用线切割机切成薄片,进一步机械减薄。

(按平面样品制备方法)
截面样品制备工艺图
线锯、片锯


线锯、片锯
2.5mm
~2mm
0.5mm
生长面衬底
三粉末样品制备
1.粉碎研磨
研磨后的粉末放在无水乙醇溶液里,用超声波震荡均匀后滴在微栅上,干燥后进行透射电镜观察。

2.树脂包埋
理想的包埋剂应具有:高强度,高温稳定性,与多种溶剂和化学药品不起反应,如丙酮等,常用的几种包埋剂:G-1,G-2,610,812E。

第四讲-TEM样品制备

第四讲-TEM样品制备
适用于生 物试样 适用于金属材 料 无机非金属材料大多数为多 相、多组分的的非导电材 料,上述方法均不适用。60 年代初产生了离子轰击减薄 装置后,才使无机非金属材 料的薄膜制备成为可能。
电解双喷法
1.冷却设备;2.泵、电解蔽 ;3.喷嘴 4.试样 5.样品 架; 6.光导纤维管
二、块体脆性样品制备流程
二级复型照片
回火组织中析出的颗粒状碳化物
解理断口上的河流花样
30CrMnSi钢回火组织
低碳钢冷脆断口
3、萃取复型
既复制试样表面的形貌,同时又把 第二相粒子粘附下来并基本上保持原来的分布状态 不仅可观察基体的形貌,直接观察第二相的形态和分布状 态,还可通过电子衍射来确定其物相。因此,萃取复型兼有 复型试样与薄膜试样的优点。
2.3 透射电镜分辨本领和放大倍数的测定
•点分辨本领的测定: 将铂、铂铱合金或铂钯 合金,用真空蒸发的方式可 以得到粒度为0.5~1nm、间 距为0.2~1nm的粒子,将其 均匀分布在火棉胶(或碳) 支持膜上,在高放大倍数下 拍摄成像。为了保证测定的 可靠性,至少在相同条件下 拍摄两张底片,然后经光学 放大(5倍左右),从照片上 找出粒子最小间距, 除以总 的放大倍数,即可得相应的 点分辨本领。
一、直接样品的制备 1.粉末样品的制备
步骤一、超声波分散
避免颗粒团聚,造成厚度增加
步骤二、将分散悬浮液滴于铜网或微姗网
步骤三、烘干分散液
烘烤时间约20分钟
2.块状样品的制备
块状材料是通过减薄的方法(需要先进行机械或化学 方法的预减薄)制备成对电子束透明的薄膜样品。减薄的 方法有超薄切片、电解双喷和离子减薄等。
晶格分辨本领的测定 利用外延生长方法所制定向单晶薄膜为标样,拍摄晶格像。 晶 体 铜酞青 铂酞青 亚氯铂 酸钾 衍射面 (001) (001) (001) (100) 晶面间距 (nm) 1.26 1.194 0.413 0.699 钯 晶 体 金 衍射面 (200) (220) (111) (200) (400) 测定晶格分辨本领常用晶体 晶面间距 (nm) 0.204 0.144 0.224 0.194 0.097

TEM制样技术经典课件

TEM制样技术经典课件

普通微栅
小孔微栅
FIB微栅
碳支持膜
当样品放在电镜中观察时,“载网支持膜”在电子束照射下,会产生电荷积累,引起样 品放电,从而发生样品飘移、跳动、支持膜破裂等情况。所以,人们考虑在支持膜上喷 碳,提高支持膜的导电性,达到良好的观察效果。这种经过“喷碳的载网支持膜”,简 称“碳支持膜”,一般膜厚度为7-10nm。 碳支持膜是以有机层为主,膜层较薄,背底一 般影响很小。通常用水或乙醇分散样品,支持膜均不会受腐蚀。载网材料有镍网和钼网 两种;如果您的样品属于磁性粉末样品可以使用两种方法:1.树脂包埋,超薄切片;2.可 以使用双联网碳支持膜。
载网(铜网、镍网、金网、钼网)
环类(单孔环、椭圆环)
三、透射电镜样品的制备
可供透射电镜观察的样品很多,有金属材料、非金属材料, 有小到几十纳米的粉末颗粒,亦有只有几个纳米厚的薄膜,还 有生物等有机材料。
只要能将其制成对电子束透明、表面平整、稳定、易于放 置、耐电子束轰击、不易挥发、不失真、无放射性、可供观察 的样品即可。
TEM制样技术
透射电镜制样用工具类
一、载网类 (纯碳膜、超薄碳膜、微栅、铜网、铜环)—参考网站:新兴百瑞
微栅类:微栅是支持膜的一个品种,在制作支持膜时,特意在膜上制作的微孔, 所以也叫“微栅支持膜”,它也是经过喷碳的支持膜,一般膜厚度为1520nm。它主要是为了能够使样品搭载在支持膜微孔的边缘,以便使样品“无 膜”观察。无膜的目的主要是为了提高图像衬度。所以,观察管状、棒状、 纳米团聚物等,常用“微栅”支持膜,效果很好。特别是观察这些样品的高 分辨像时,更是最佳的选择;碳膜厚度可根据用户使用情况特制;如果样品 颗粒尺寸小于10nm,请用超薄碳膜。
2、平面样品的制备
制样设备: 本实验室目前电镜制样的设备主要有离子减薄、凹坑仪、金刚石 圆片切割仪、电解双喷、机械冲孔、磁控溅射镀膜、超声冲孔等实验设备, 能对薄膜样品、金属块体样品进行制备。

TEM生物样品特殊制备技术课件

TEM生物样品特殊制备技术课件

硫胺焦磷酸酯酶(TPP)技术获得的选择性染色。大鼠附睾细胞 内的高尔基器只有内层着色。(×33000)
肝细胞中毛细胆管呈现ALP反应阳性(箭头)×15000
第四节、免疫电镜技术 Immuno electronmicroscopic technique
1、概念:
免疫电镜技术是免疫学和电镜技术的结合,其特点是将免疫 学中抗原抗体反应的特异性与组织化学中形态学的可见性,结合 电镜的高分辨能力和放大本领,用胶体金标记抗原,在亚细胞水 平上研究组织和细胞的形态与功能,还可进行细胞内抗原的定性 定位研究,从而将细胞结构与功能代谢紧密结合起来。
醛类物质对不同细胞器的固定和对酶的活性作用
细胞器 胞基质 内质网 线粒体 核周隙 GOL体 酶活性 戊二醛 +++ +++ +++ +++ +++ 一般
甲 醛 ++ +++ +++ ++ ++ 优秀
在选择固定剂时,首先考虑保存酶的活性,后考虑结构的 保存。由表可见,戊二醛的固定作用优于甲醛,而甲醛保存酶 的活性作用大于戊二醛。因此电镜细胞化学技术中常用戊二醛 和甲醛的混合液进行样品固定。
从理论上讲,若想保存好样品,需充分固定。但固定越彻底, 酶的失活越严重。要想保存酶的活性,最好是先孵育后固定,但 先孵育导致细胞微细结构的损伤,反应不均,酶反应物扩散、流 失,出现与酶无关部位定居的假象。这些矛盾是EM细胞化学技术 中的难点。在EM酶细胞化学技术中酶的失活、丢失是不可避免的, 细胞微细结构的破坏也是不可避免的但是应当尽量减少固定剂造 成酶的失活与丢失,减少孵育液对细胞微细结构的损伤破坏。
5、免疫金标记技术的应用
(1)免疫金标记技术是金探针作为抗体与组织和细胞内抗原 发生抗原抗体特异性反应,使金颗粒附着在反应部位,定位准 确,金颗粒电子密度很高,EM下清晰可辨。 (2)商品化的金探针购买方便,价格低廉。根据实验要求可 选择大小直径不同的胶体金颗粒(如3nm、5nm、10nm ……) (3)在超微结构水平上观察研究细胞表面和细胞器中的特异 抗原和抗体等物质。也可对突触小泡内神经递质进行标记。

TEM 原理及制样

TEM 原理及制样

Lecture13:TEM sample preparationContents1TEM sample holders1 2Parts of a TEM holder42.1Types of TEM holder (5)2.2In-situ TEM holders (6)3TEM sample preparation93.1Electrolytic polishing (9)3.2Ion milling technique (12)3.3Cross section sample preparation (17)3.4Replica technique (18)4Focused ion beam TEM sample preparation20 1TEM sample holdersThe specimen holder is used to insert the sample into the TEM from outside for imaging.The sample is loaded onto the TEM stage for imaging.Now, TEM holder and stage are essentially integrated.The TEM holder plays and important role since it allows for introduction of a sample in ambient conditions into an instrument that is held in ually the holder region is pumped separately before the sample is fully introduced in the TEM.A schematic diagram of some of the pumps used in the TEM is showed infigure1.There are2main types of holder in the TEM1.Top loading-the sample has no connection to the outside.After de-livery of the sample to the stage the holder is withdrawn.Top loading holders were used in earlier instrument version,especially for high res-olution since this minimizes external vibrations.A schematic of a top loading holder is shown infigure2.1MM3030:Materials CharacterisationFigure1:Pumping system in a TEM.Taken from Transmission Electron microscopy-Williams and Carter.2MM3030:Materials CharacterisationFigure2:Top entry loader in(A)cross section and(B)top view.Taken from Transmission Electron microscopy-Williams and Carter.3MM3030:Materials CharacterisationFigure3:Schematic of a side entry holder.Taken from Transmission Electron microscopy-Williams and Carter.2.Side loading-these are the most commonly used holders now.Theadvantage of the side loading holders is that it is possible to provide external stimuli(heat,current,load)while imaging.2Parts of a TEM holderThe focus will be on the side loading holder since it is ubiquitous in use.A schematic of the holder is shown infigure3.Various parts of the holder can be identified from thefigure1.O-ring-Provides the mechanical link to the TEM column.The o-ringseparates the portion of the holder in the ambient from the portion in vacuum.Typically a viton o-ring is used and some holders have more than one.The o-rings are usually greased but the excess grease should be removed before inserting in the TEM since this can affect the vacuum.The way in the holder is inserted in the instrument depends on the specific TEM.2.Jewel bearing-This provides the other mechanical link of the holderto the TEM.This is used for mechanical translation of the sample(in the x-y plane).3.The cup-this actually holds the sample.Typical TEM samples are3mm discs though bulk holders are available(not very common).4.Clamping ring-this clamps and holds the sample in place.Both thecup and the clamping ring are exposed to the electron beam and hence4MM3030:Materials CharacterisationFigure4:Some types of side entry holders.From top a rotation holder, heating holder,cooling holder,double-tilt,and single-tilt holder.Taken from Transmission Electron microscopy-Williams and Carter.should be made of a material with low x-rayfluorescence.Be is the material most commonly used.2.1Types of TEM holderThere are various designs for the side entry holder.Some of them are shown infigure4.1.Single tilt holder-most commonly used holder.Tilting around theaxis of the holder is possible.Shown infigure4.2.Quick change holder-this is a single tilt holder with a clamp instead ofeful for quick change of samples.Philips CM12series TEMs have a quick change holder.3.Multiple specimen holder-some holders can hold more than one sample.5MM3030:Materials CharacterisationFigure5:Single tilt holder with2and5specimen cups.Taken from Trans-mission Electron microscopy-Williams and Carter.This is again for multiple sample preparation.These are usually single tilt holders.Multiple tilt holders are shown infigure5.4.Bulk specimen holders-These are used for bulk specimens that cannotbe made into3mm disks.This is not very common.The area of interest should still be thin enough for the electron beam to pass through.5.Double tilt holder-two tilt angles are possible-in-plane and out-of-plane.This is most commonly used for diffraction and imaging.6.Tilt-rotate holder-this allows to select the tilt axis and then rotatethe specimen.7.Low-background holder-the cup and clamping ring are made of Be.Mainly used for x-ray studies(EDAX)since Be has low x-rayfluores-cence.2.2In-situ TEM holdersOne of the advantages of a side loading holder is that it is possible to have signals from the outside to interact with the sample while imaging.This gives added functionality to the TEM and provides for direct structure-property correlations.Some of the in-situ TEM holders are1.Heating holder-for heating samples ually a resistive heateris used with temperatures as high as1000◦C possible.Care should be6MM3030:Materials CharacterisationFigure6:Bulk specimen holder.Taken from Transmission Electron mi-croscopy-Williams and Carter.taken not to weld the sample to the holder.A heating holder is shown infigure4.2.Cooling holder-holders can go up to liquid nitrogen(77K)or heliumtemperatures(4K).This is mainly used for biological samples,where beam damage is minimized by cooling the sample.A holder is shown infigure4.3.Cryo-transfer holder-cooling holder with cryo-transfer so that thesample is never heated to room temperature.4.Straining holder-holder is used for applying external strain to theTEM ually piezoelectric actuators are used for precise strain application.They can be combined with other in-situ holders,like heating holder,likefigure5.EBIC and CL holders-these can supply electrical current to the sam-ple.There are a number of in-situ holders developed by specific research groups. For example,in-situ thermal evaporation is possible in the TEM.Similarly dynamic TEM holders are available for driving in-situ reactions at high heat-ing rates combined with diffraction measurement.7MM3030:Materials CharacterisationFigure7:Strain holder with heating.Taken from Transmission Electron microscopy-Williams and Carter.8MM3030:Materials Characterisation 3TEM sample preparationSample preparation is an important part of TEM analysis.There are two main criteria for TEM sample preparation1.The sample should be electron transparent.If not the whole sampleat least the ROI should be thin.Typical thickness values for metallic samples should ually,100nm is a upper limit for the sample thickness.2.The sample should be mechanically robust for handling.Usually,the sample to be investigated is directly prepared from the under-lying specimen.Sometimes for bulk specimens replica samples are prepared. This is mainly for studying surface topographies and precipitates.TEM sam-ples are either self-supported or mounted on a grid for analysis.Copper grids are the most commonly used,though for high temperature work Mo grids are used.For nanoparticles and thinfilms a-Cfilm is used as support.a-C has low contrast in the TEM and will not obscure the contrast arising from the specimen.Some typical TEM grids are shown infigure8.The TEM preparation technique depends on the type of sample and also on the property of interest.Mechanical damage during sample preparation might be of an issue for studying dislocation densities in a specimen.Simi-larly cross sectional TEM preparation might be necessary for some samples, which can be a time consuming process.For most samples we need to pre-thin the sample to an initial thickness of100-200µm.Cut a3mm disk from the sample(for bulk specimens).Thin the central disk to a fewµm and then thin further(by different techniques)till sample is electron transparent. Sample sizes in the different stages of TEM preparation are shown infigure 9.3.1Electrolytic polishingElectrolytic polishing is used for conducting samples like metals/alloys in order to produce samples that are electron transparent.The initially sheet thickness can be around a few hundredµm.This can be prepared by rolling or grinding bulk specimens.Similarly,metal coatings on substrates can be peeled offand used for thefinal thinning.Thin discs can also be cut from bulk specimens.This process is called coring.Some of the different equip-ment for coring is shown infigure10.There will be some mechanical damage at the surface due to coring but these can be removed during polishing. These discs are thinned by electrolytic polishing.The most common elec-9MM3030:Materials CharacterisationFigure8:Typical TEM grids.Taken from Transmission Electron microscopy -Williams and Carter.Figure9:Stages in the TEM sample preparation from a bulk specimen. Taken from TEM sample preparation-Sridhara Rao et al,Microscopy:Sci-ence,Technology,Applications and Education.10MM3030:Materials CharacterisationFigure10:Different coring tools(A)mechanical punch(B)Abrasive-slurry disc cutter(B)Ultrasonic cutter(D)Spark-erosion cutter.Taken from Trans-mission Electron microscopy-Williams and Carter.11MM3030:Materials Characterisation trolytic polishing technique is the window technique.The sample is made the anode and a thin stainless sheet is made the cathode.The sample is immersed in the electrolyte,which is usually cooled by water or liquid nitro-gen.Perchloric acid is usually used as the electrolyte.The sample edges are covered by lacquer to expose a’window’,hence the name.The experimental setup and the hole generation are shown infigure11.When a current is applied the material is dissolved from the anode(sample) and deposits on the cathode.The rate of dissolution depends on the cur-rent and applied voltage.The I−V characteristics are shown infigure12. Depending on the current and voltage,there are three regimes-etching,pol-ishing,and pitting.The edges are coated so that material removal will start within the window.Once a hole is formed within the window the sample is pulled out.The region around the hole is usually electron transparent and can be mounted on a TEM grid.The problem with this technique is that it is hard to control the location of the hole in the window.A modification to the window technique is the Bollmann technique.A pointed cathode is used to form an initial hole in the location of choice and this is then replaced byflat electrodes to expand the electron transparent re-gion.A variation of the Bollmann technique,which is very commonly used, is the Jet polishing technique.A schematic of the jet polishing technique is shown infigure13.Here the electrolyte is locally sprayed on the sample, using pointed electrodes.The jet helps in polishing from both ends of the sample and hence it is faster.The method also reduces electrolyte use and can produce large electron transparent areas.The electrolyte polishing technique can be used for samples that are conduct-ing-mostly metals and alloys.For non-conducting samples like ceramics, semiconductors,depositedfilms,other TEM sample preparation techniques are needed.3.2Ion milling techniqueFor non-conducting samples usually grinding and polishing steps are used in order to reduce sample thickness.Some an ultramicrotome is used in order to generate thin samples.These can be either electron transparent or can be used as the starting material for further thinning.The schematic of the technique is shown infigure14.For samples,where ultramicrotome cannot be used then a standard tripod polisher is used in order to thin the sample. This produces samples that are a fewµm thick.Thefinal polishing step is done by an ion beam miller.The schematic of the ion beam miller and an actual instrument are shown in figure15.The sample is bombarded by high energy ions or neutral atoms.12MM3030:Materials CharacterisationFigure11:Window polishing technique.Taken from Transmission Electron microscopy-Williams and Carter.13MM3030:Materials CharacterisationFigure12:I−V characteristics during polishing.Taken from Transmission Electron microscopy-Williams and Carter.Figure13:Schematic of the jet polishing technique.Taken from Transmis-sion Electron microscopy-Williams and Carter.14MM3030:Materials CharacterisationFigure14:Schematic of ultramicrotome technique.Taken from Transmission Electron microscopy-Williams and Carter.15MM3030:Materials CharacterisationFigure15:Schematic of ion beam milling technique.Taken from Transmis-sion Electron microscopy-Williams and Carter.16MM3030:Materials CharacterisationFigure16:Penetration vs.thinning as a function of beam incidence.Taken from Transmission Electron microscopy-Williams and Carter.Usually Ar ions are used and they are formed by passing the Ar gas though a high voltage(4-6keV).The sample is held in vacuum and also usually cooled by liquid nitrogen.The ions are incident on the sample and sputter material away.To minimize ion penetration the beam is usually incident at a low angle( 20◦)though if the angle is very small the sputter rate is small.The trade offbetween ion penetration and thinning rate is shown in figure16.Ion beam is highly controlled and a localized process but it is time consuming.Sputter rates are usually a few˚A per second so that creating an electron transparent sample can take hours,especially if the initial thickness is high.3.3Cross section sample preparationCross sectional samples are routinely interrogated in the TEM,especially for studies of interface.The schematic of the cross section process is shown in figure17.Slices from the sample are cut using a diamond slicer.These slices are placed between spacer layers and then glued on to a grid.The slices are glued in such a way that the interface is parallel to the slot in the grid. This sample is then thinned by standard tripod polishing until it is a few µm thick.Thefinal sample is thinned using a ion beam miller to create an electron transparent sample.17MM3030:Materials CharacterisationFigure17:Cross sectional sample preparation.Taken from Transmission Electron microscopy-Williams and Carter.3.4Replica techniqueReplica technique is used for studying bulk specimens which cannot be de-stroyed to prepare electron specimens.It is also useful for studying surface topography features and precipitates though SEM techniques have gradually replaced replica sample preparation.The schematic of the replica technique is shown infigure18.A replica of the sample surface is prepared using a plastic mold.The mold is then removed from the surface and the surface of the specimen is replicated by the surface of the plastic.A thinfilm of carbon or metal like Cr,Pt is evaporated on the surface of the plastic.Sometimes the evaporation is done from an oblique angle,shadow evaporation,to en-hance the contrast.The plastic is removed by dissolving in a suitable solvent and thefilm is thenfloated on to a grid for analysis.A variation of the replica technique is the extraction replica technique.As the name implies,it is used to extract and study precipitates embedded in a matrix.The schematic of the process is shown infigure19.The bulk sample is etched in order to expose the precipitates.A Cfilm is then evaporated on the sample and then etching is continued until the bulk material is removed leaving behind the precipitates.A TEM image of precipitates removed by the extraction technique is shown infigure20.18MM3030:Materials CharacterisationFigure18:Replica technique for sample preparation.Taken from Transmis-sion Electron microscopy-Williams and Carter.Figure19:Extraction replica technique for sample preparation.Taken from Transmission Electron microscopy-Williams and Carter.19MM3030:Materials CharacterisationFigure20:TEM image of sample prepared by extraction replica technique. Taken from Transmission Electron microscopy-Williams and Carter.4Focused ion beam TEM sample prepara-tionFocused ion beam(FIB)instrument along with SEM is becoming increas-ingly important in TEM sample preparation.The advantage of FIB-SEM is that it is possible to prepare TEM specimens from precise locations in the sample.This is not possible in other techniques since there is always some uncertainty from where thefinal TEM sample will be obtained.One area where the FIB is used extensively is in the microelectronics industry for evaluation of defects in parts of the micro-chip.Here the area to be investi-gated is of the order of tens of nm s,so that conventional TEM preparation techniques cannot be used.The schematic of the2beam FIB-SEM is shown infigure21.The FIB can be considered as an ion beam miller except that Ga ions are used instead of Ar ions in a conventional ion beam miller.The Ga ions are originated from a liquid metal source(Ga melting point is30◦C).The beam is accelerated and scanned over the specific portion of the specimen for milling.Modern FIB-SEM also have gas-injection systems(GIS)for Pt deposition and a mi-cromanipulator(Omniprobe)for removing the specimen from the sample and attaching to the TEM grid.The steps involved in sample preparation are1.Identification of the ROI.2.Deposition of a Pt layer on top of this region.Pt deposition is done20MM3030:Materials CharacterisationFigure21:Schematic of the2beam FIB-SEM.Taken from Transmission Electron microscopy-Williams and Carter.using the GIS.The Pt deposition is done over a region fewµm long and wide and a few nm thick.3.The Ga ions are used to ion mill the region around the Pt layer to createa trench.Sample can be manipulated in-situ with three dimensionaltranslation and rotation possible.The Pt layer is also cut from below to create a lamellar.4.The Omniprobe is used to lift this lamellar from the sample and thenattach it to the TEM grid.The Pt metal is used to weld the lamellar to the grid.5.Thefinal cleaning of the lamellar is done using the Ga ions.Finalthinning to electron transparency is also done.The various stages in making the lamellar are shown infigure22.The entire TEM preparation is done in-situ and the SEM is used for imaging the sample preparation.The FIB can also be used for imaging.The FIB-SEM instru-ment and the electron and ion beam column is shown infigure23.The TEM sample before lift-offand thefinal sample attached to the grid is shown in figure24.Thefinal sample has dimensions of the order ofµm but its thick-ness is of the order of nm,so that it is electron transparent.The FIB-SEM technique is the most versatile of the TEM sample preparation techniques since it can be used for both conducting and insulating samples.It also al-lows for the preparation of TEM samples from specific areas of the sample. But sample preparation and manipulation using the FIB-SEM is technically challenging.21MM3030:Materials CharacterisationFigure22:Stages in creation of the lamella from a specimen are shown. Taken from Transmission Electron microscopy-Williams and Carter.22MM3030:Materials CharacterisationFigure23:Dual beam FIB-SEM instrument with the close-up of the elec-tron and ion beam column.Taken from Transmission Electron microscopy-Williams and Carter.23MM3030:Materials CharacterisationFigure24:TEM lamellar before lift-offand thefinal sample attached to the TEM grid.From P.Swaminathan-unpublished.24。

TEM制样PPT-3

TEM制样PPT-3

粉末样品制备工艺图
聚四氟乙烯包埋槽从包埋槽中取出的粉末样品
粉末样品
Si片
包埋后切成条样品用Si片夹紧
四氩离子减薄
1. 离子减薄原理
2. 影响样品制备的几个因素
3. 离子减薄仪器
1. 离子减薄原理
在电场作用下氩气被电离成带Ar+的氩离子,带着一定能量的氩离子从阳极飞向阴极,通过阴极孔,打在接地的样品表面,使样品表面溅射,这就是氩离子轰击的基本原理。

2.影响样品制备的几个因素
●与仪器有关的
A、离子束电压
B、离子束电流(氩气的流量)
C、离子束的入射角
D、真空度
●与样品有关的
A、样品的种类(性质)
B、样品的微结构特点
C、样品的初始表面条件
D、样品的初始厚度
E、样品的安装
3.离子减薄仪器
●宽束离子减薄仪
●低角度离子减薄仪
●聚焦离子束减薄仪
500V一2.5kV ●低能离子减薄仪
氩离子减薄后的Si 材
料薄膜样品
对粘样品窄窄的缝宽度三十纳米
材料中心部分厚度1
微米左右
样品表面明显损伤
加速电压过高造成
的损伤Si 衬底上多层膜截面样
品的高分辨像
减薄后样品逢裂开
减薄前表面状态不好,造成的损伤
加速电压过高造成
的损伤GaAs/InGaAs 量子点
GaAs/InGaAs 量子
点高分辨
GaAs/InGaAs 量子点形貌像。

TEM 制样方法

TEM 制样方法

• 钉薄轮的选择
钉薄仪所配的轮子有不锈钢论;磷铜轮;毛毡 轮等,根据材料的不同选择不同材质、不同直径的 钉薄轮。
平轮 :用于大块减薄 钉薄轮 :用于钉薄 毛毡轮:用于抛光
平轮
钉薄轮
不锈钢轮
抛光轮
• 磨料的选择
应用较广泛的是金刚石膏,但对于金属材料不 适用,金属材料用立方氮化硼(CBN),两者混合 起来用于复合材料,较软的金属合金也适用。
Si衬底上多层膜截面样 品的高分辨像
1. 选样品 2. 样品的清洗处理 3. 对粘样品
1. 选样品
低倍立体显微镜下选样品,表面平坦,没 有损伤,不选样品的边缘。用线锯或解理刀把 样品切成小块,样品的对角线不超过3mm即 可。
2. 清洁处理
无水乙醇------丙酮------两次超声清洗,每次 2至3分钟。
3. 对粘样品
清洗后的样品从丙酮里捞出来,自然干燥 后,在样品的生长表面里涂上少量胶(MBond610),将两块样品的生长面,面对面粘在一 起,快速放入夹具中加压,固定,在130℃ 左右的 加热炉上固化两小时以上,冷却后取出,用线切割 机切成薄片,进一步机械减薄。(按平面样品制备 方法)
如用4°离子入射角,在边缘不挡住中心部分 的条件下,可得到的最大钉薄深度为: 1.1mm×tan4°=77(μm)。
样品盘几何
• 不同的钉轮直径可获得的钉薄深度
钉轮直径 钉薄深度 (mm) (μm)
10
121
15
80
20
60
25
48
左表说明10mm直径 的钉轮不适合于样品的制
备,因为钉薄的深度〉 77μm,边会挡住中心部 分,15mm的直径似呼超 过了极限,但在实践中的
生长面

TEM制样方法

TEM制样方法

• 玻璃片长板向内,插入卡 槽
• 注意推入和拉出都不要碰 触刀片,防止污染
刀片
数据处理
• 安装Search Match • 将要导入的txt文本数据前面的文字部分全部删掉,只剩下纯数据。
双击打开Search Match软件;导入XRD数据(File→Import→Profile Data→文件类型:All files; Format:Two Column Text→选中要导入的XRD数据→确定)
导入数据 后
点击setting→Restrictions→弹出对话框
选择Must Include→选择样品中可能的元素 (如本样品是Ni,有可能被氧化,选择Ni和O 两个元素)→选中Only Selected element→确 定
选中卡片检索图标 →弹出对话框→选择“否”→将出现一系列待选卡片
TEM
透射电子显微镜
制样方法:
• 取微量样品,用无水乙醇(or正庚烷)溶解样品,超声10-15min • 样品溶液需要澄清,透明度要求能看到实验服
• 滴几滴乙醇在桌面上,卫生纸擦干净桌面 • 镊子超声一会,乙醇淋洗,甩干备用 • 取滤纸放在桌面上,用镊子从铜网盒里夹起铜网备用
• 移液枪调至50µL,吸取样品溶液 • 右手拿镊子夹起铜网,悬空平放;左手拿移液枪,枪头悬在铜网上方,
将主要衍射峰对应的比较好的卡片选中,拖至卡片上方的空白区域。
选中在空白区域的卡片,右击→Analyse Match...→弹出对话框→看主要 衍射峰的匹配情况。(主要是看匹配的好坏)
主要衍射峰 对应的角度
全部 匹配
是否匹 配
双击匹配较好的卡片→双击→查看卡片的详细信息。(此图为出现的页面的 上半页)
卡片名称 晶型

TEM(2)制样技术

TEM(2)制样技术

离子减薄
• 离子减薄是物理方法减薄,它 • 离子减薄是物理方法减薄, 采用离子束将试样表层材料层 层剥去, 层剥去,最终使试样减薄到电 子束可以通过的厚度。 子束可以通过的厚度。 • 图7-7是离子减薄装置示意图。 是离子减薄装置示意图。 试样放置于高真空样品室中, 试样放置于高真空样品室中, 离子束(通常是高纯氩) 离子束(通常是高纯氩)从两 侧在3 5KV加速电压加速下轰 侧在3-5KV加速电压加速下轰 击试样表面, 击试样表面,样品表面相对离 子束成0 30º角的夹角 角的夹角。 子束成0-30 角的夹角。 • 离子减薄方法可以适用于矿物、 离子减薄方法可以适用于矿物、 陶瓷、 陶瓷、半导体及多相合金等电 解抛光所不能减薄的场合。 解抛光所不能减薄的场合。 离子减薄的效率较低, 离子减薄的效率较低,一 般情况下4μm/小时左右。 4μm/小时左右 般情况下4μm/小时左右。 但是离子减薄的质量高薄 区大。 区大。
第2节 TEM制样技术 制样技术
透射电子显微镜样品制备
• 透射电子显微镜成像时,电子束是透过样 透射电子显微镜成像时, 品成像。由于电子束的穿透能力比较低, 品成像。由于电子束的穿透能力比较低, 用于透射电子显微镜分析的样品必须很薄。 用于透射电子显微镜分析的样品必须很薄。 根据样品的原子序数大小不同, 根据样品的原子序数大小不同,一般在 50~500nm之间 之间。 50~500nm之间。 • 制备透射电子显微镜分析样品的方法很多, 制备透射电子显微镜分析样品的方法很多, 这里介绍几种常用的制样方法。 这里介样品三个步骤:
• 第一步是从大块试样上切割厚 第一步是从大块试样上切割厚 度为0.3 0.5mm厚的薄片 0.3—0.5mm厚的薄片。 度为0.3 0.5mm厚的薄片。 • 电火花线切割法是目前用得最 广泛的方法,见图7 广泛的方法,见图7-5。 • 电火花切割可切下厚度小于 0.5mm的薄片 的薄片, 0.5mm的薄片,切割时损伤层比 较浅, 较浅,可以通过后续的磨制或 减薄除去. 减薄除去.电火花切割只能用 导电样品. 导电样品. • 对于陶瓷等不导电样品可用金 刚石刃内圆切割机切片. 刚石刃内圆切割机切片.
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• 双面胶上可以直接贴样品,也可以将铜网贴在上面看样,但 是铜网贴过以后就不能回收了
• SEM和EDS用一样的样品台,区别在于SEM要用黑色的导电 胶,EDS用普通的双面胶即可
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数据处理:
• 测完样以后的反馈的数据有三种类型
• 图片即为成品图 • Word文档里有具体的百分比含量 • txt文本是原始数据,不想直接用原图的可以用origin导入原始数
卡片名称 晶型
晶格参数
晶格参数的参考值
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(此图为出现的页面的下半页)
晶面
晶面间距(单位不是nm) 峰的强度
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用Origin软件做XRD图
(峰的高低和宽窄代表着晶粒的大小和结晶度的高 低,峰越尖晶粒越小,峰越窄晶粒结晶度越好)
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双击origin图标打开软件→File →Import→Single ASCII→选择 要导入的文件导入数据。
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将主要衍射峰对应的比较好的卡片选中,拖至卡片上方的空白区域。
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选中在空白区域的卡片,右击→Analyse Match...→弹出对话框→看主要 衍射峰的匹配情况。(主要是看匹配的好坏)
主要衍射峰对 应的角度
全部 匹配
是否匹 配
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双击匹配较好的卡片→双击→查看卡片的详细信息。(此图为出现的页面的 上半页)
据作图
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• 通过图片,就可以直观地观察到样品的大致元素含量
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TEM
透射电子显微镜
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制样方法:
•取微量样品,用无水乙醇(or正庚烷)溶解样品,超声10-15min •样品溶液需要澄清,透明度要求能看到实验服
•滴几滴乙醇在桌面上,卫生纸擦干净桌面 •镊子超声一会,乙醇淋洗,甩干备用 •取滤纸放在桌面上,用镊子从铜网盒里夹起铜网备用
•移液枪调至50µL,吸取样品溶液
•右手拿镊子夹起铜网,悬空平放;左手拿移液枪,枪头悬在铜网上 方,控制速度,一滴一滴将样品溶液滴在铜网上
•将滤纸和铜网一起放在红外烘箱里烘干1~2min
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数据处理
标尺
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成品图:
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模板:
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XRD
X射线衍射仪
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制样方法:
• 将样品研成粉末状 • 测样时将样品平铺在玻璃片的磨砂槽内,稍稍用力压实 • 样品铺好后将卡槽周围擦干净
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双击横纵坐标旁的文 字,进行修改。(如 右图所示。)
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右击→Add Text...→输入晶面→Copy Page→粘贴在Word里(至此结束)
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EDS
能谱
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制样方法:
• EDS放置样品的样品台
• 制样前将样品磨成粉末
• 将双面胶剪成一个形状贴在样品台上 • 牙签挑起微量样品,平铺在双面胶上 • 牙签将样品用力压实压紧,要保证样品不会洒落 • 用洗耳球用力鼓吹,吹去多余的粉末 • 擦干净样品台的表面,再贴下一个样
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•玻璃片长板向内,插入卡 槽 •注意推入和拉出都不要碰 触刀片,防止污染
刀片
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数据处理
• 安装Search Match • 将要导入的txt文本数据前面的文字部分全部删掉,只剩下纯数据。
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双击打开Search Match软件;导入RD数据(File→Import→Profile Data→文件类型:All files; Format:Two Column Text→选中要导入的XRD数据→确定)
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选中要导入的两列数据→点击 点线图标。
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双击横纵坐标轴→在弹出的对话框中修改横纵坐标的取值范围。
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选中图旁边的文本 框→右击→选择 cut→删除多余的 文本框。
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再次双击坐标轴→ 在弹出的对话框中 选择Title&Format →勾选Show Axis & Tich→选择上方(TOP) 的坐标轴→将Major 和Miner都改为 None→确定。(再 做一次,选择右边 Right坐标轴→确保 将图形围起来。)
导入数据 后
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点击setting→Restrictions→弹出对话框
选择Must Include→选择样品中可能的元素 (如本样品是Ni,有可能被氧化,选择Ni和O 两个元素)→选中Only Selected element→确 定
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选中卡片检索图标 →弹出对话框→选择“否”→将出现一系列待选卡片
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