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Schottky defect

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Published: 01 January 2003
Fig. 1 Defects in ionic crystals. (a) Schottky defect. (b) Frenkel defect. Vacancies (V X , V Me ) are indicated by open squares. Interstitial ion (Me i ) is shown as shaded circle. More
Image
Published: 01 January 1997
Fig. 10 Schottky defects in an ionic crystal. Cations are represented by solid circles and anions by shaded ones. Equal numbers of cation and anion sites are vacant so as to preserve charge neutrality. Source: Ref 5 More
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003589
EISBN: 978-1-62708-182-5
... Abstract This article describes the Schottky defect and the Frenkel defect in oxides. It provides information on the p-type metal-deficit oxides and n-type semiconductor oxides. The article discusses diffusion mechanisms and laws of diffusion proposed by Fick. It explains the oxide texture...
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003709
EISBN: 978-1-62708-182-5
... Common point defect structures found in inorganic compounds are briefly described ( Ref 15 ). Kröger-Vink notation is used to describe the defect equilibria. Schottky defects are found in stoichiometric compounds and consist of equivalent concentrations of anion and cation defects. An example would...
Series: ASM Handbook
Volume: 20
Publisher: ASM International
Published: 01 January 1997
DOI: 10.31399/asm.hb.v20.a0002460
EISBN: 978-1-62708-194-8
... to their melting point. A somewhat different type of “vacancy” found in ionic solids is illustrated in Fig. 10 . Here, to maintain electrical neutrality, there must be an equal number of cation and anion vacancies; thus “double” vacancies ( Schottky defects ) are formed. Fig. 9 Two-dimensional...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006681
EISBN: 978-1-62708-213-6
... are summarized in Table 2 . Features of electron sources used in transmission electron microscopy Table 2 Features of electron sources used in transmission electron microscopy Features Type of electron source Tungsten hairpin LaB 6 Schottky field-emission gun Cold field-emission...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006644
EISBN: 978-1-62708-213-6
... dislocation defects stacking faults Overview Introduction—History and Development Trends X-ray topography is the general term for a family of x-ray diffraction imaging techniques capable of providing information on the nature and distribution of imperfections, such as dislocations, inclusions...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006670
EISBN: 978-1-62708-213-6
... and photovoltaics. These materials by definition contain structural defects. In the case of polycrystalline materials, these consist of grain or phase boundaries, dislocations, and various point crystal defects. One way to conceive of amorphous materials is that they lie at the end of a continuum, where the density...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006668
EISBN: 978-1-62708-213-6
...-emission sources primarily rely on an electrostatic field for electron beam generation. Fig. 2 Schematics of conventional (a) thermionic tungsten hairpin filament gun and (b) Schottky field-emission gun. Adapted from Ref 3 Thermionic emission sources heat a tungsten filament or La/CeB 6...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006769
EISBN: 978-1-62708-295-2
... electrons from a tungsten filament are termed cold-field-emission SEMs, or high-resolution SEMs, and have the highest resolution capabilities of all SEMs. A compromise is reached in the thermal-field-emission (or Schottky gun) SEM when a combination of heat and electric field are used to produce an electron...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0001822
EISBN: 978-1-62708-180-1
... of copper-penetration fractures. The Chesapeake & Ohio Railroad reported on an investigation that began in 1952 to determine what could be done to reduce or eliminate wrecks and hot-boxes due to defective journals. The railroad developed a journal-inspection car that used ultrasonic inspection. During...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006943
EISBN: 978-1-62708-395-9
... filaments. Both types of the hexaboride-type emitters require better vacuum than tungsten filament. The field-emission types used in SEM instruments are the Schottky emitter and cold-cathode emitter, both manufactured with a sharp tip. The Schottky emitter is made of a tungsten single crystal (100) coated...
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001767
EISBN: 978-1-62708-178-8
Series: ASM Handbook
Volume: 8
Publisher: ASM International
Published: 01 January 2000
DOI: 10.31399/asm.hb.v08.a0003255
EISBN: 978-1-62708-176-4
... have different charges than the host ions, the crystal must compensate structurally such that charge neutrality is maintained. This can be accomplished by the formation of lattice defects, such as vacancies or interstitials (Schottky, Frenkel defects). In ionic crystals, the presence of charged...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003533
EISBN: 978-1-62708-180-1
.... A compromise is reached in the thermal-field-emission (or Schottky gun) SEM, where a combination of heat and electric field are used to produce electrons. These machines have better resolution than conventional SEMs, while being easier to use than the high-resolution machines. A conventional SEM also...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.9781627083959
EISBN: 978-1-62708-395-9
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006660
EISBN: 978-1-62708-213-6
... disadvantage is that these sources tend to have limited lifetimes. This can be an important consideration if large-area maps are of interest. Field emission sources, specifically Schottky-type emitters, are ideal for EBSD measurements. These sources can be operated to produce high beam currents (>20 nA...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.9781627082136
EISBN: 978-1-62708-213-6
Series: ASM Handbook
Volume: 13A
Publisher: ASM International
Published: 01 January 2003
DOI: 10.31399/asm.hb.v13a.a0003671
EISBN: 978-1-62708-182-5
... is vacancy diffusion, because a metal crystal always contains a high concentration of point defects, such as atomic vacancies, while ionic oxides contain Schottky and Frenkel defects that involve vacancies. An atom or ion sitting on a lattice site can diffuse by jumping to adjacent vacant sites. For metal...
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.9781627081788
EISBN: 978-1-62708-178-8