Tilting of semi-rigid GaF6 octahedra in GaF3 at high pressures

Jens Erik Jorgensen; Yaroslav Filinchuk; Vladimir Dmitriev

doi:10.1017/S0885715616000701

Tilting of semi-rigid GaF₆ octahedra in GaF₃ at high pressures

Jens Erik Jorgensen^*, Yaroslav Filinchuk, Vladimir Dmitriev

^*Corresponding author af dette arbejde

Institut for Kemi

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

Abstract

The VF3-Type compound GaF3 has been studied by high-pressure angle-dispersive X-ray diffraction in the pressure range from 0.0001 to 10 GPa. The compression mechanism was found to be highly anisotropic. The c-Axis shows little pressure dependence (≈0.4%), but exhibits negative linear compressibility up to ≈3 GPa where it achieves its maximum length. In contrast, the length of the a-Axis is reduced by ≈8.8% at the highest measured pressure and an anomalous reduction in the linear compressibility is observed at 4 GPa. The zero pressure bulk modulus B 0 was determined to B 0 = 28(1) GPa. The compression mechanism of GaF3 is discussed in terms of deformation of an 8/3/c2 sphere-packing model. The volume reduction of GaF3 is mainly achieved through coupled rotations of the GaF6 octahedra within the entire measured pressure range, which reduces the volume of the cubooctahedral voids. In addition, the volume of the GaF6 octahedra also decreases for p4.0 GPa, but remains constant above this pressure. The volume reduction of the GaF6 octahedra is accompanied by an increasing octahedral strain. Isosurfaces of the procrystal electron density are used for visualization of the cubooctahedral voids at different pressures.

Originalsprog	Engelsk
Tidsskrift	Powder Diffraction
Vol/bind	32
Nummer	S1
Sider (fra-til)	S69-S73
Antal sider	5
ISSN	0885-7156
DOI	https://doi.org/10.1017/S0885715616000701
Status	Udgivet - 1 sep. 2017

Adgang til dokumentet

10.1017/S0885715616000701

Andre filer og links

http://www.scopus.com/inward/record.url?scp=85009403757&partnerID=8YFLogxK

Citationsformater

@article{5bcbded10c694da2b40783cff07986b8,

title = "Tilting of semi-rigid GaF6 octahedra in GaF3 at high pressures",

abstract = "The VF3-Type compound GaF3 has been studied by high-pressure angle-dispersive X-ray diffraction in the pressure range from 0.0001 to 10 GPa. The compression mechanism was found to be highly anisotropic. The c-Axis shows little pressure dependence (≈0.4%), but exhibits negative linear compressibility up to ≈3 GPa where it achieves its maximum length. In contrast, the length of the a-Axis is reduced by ≈8.8% at the highest measured pressure and an anomalous reduction in the linear compressibility is observed at 4 GPa. The zero pressure bulk modulus B 0 was determined to B 0 = 28(1) GPa. The compression mechanism of GaF3 is discussed in terms of deformation of an 8/3/c2 sphere-packing model. The volume reduction of GaF3 is mainly achieved through coupled rotations of the GaF6 octahedra within the entire measured pressure range, which reduces the volume of the cubooctahedral voids. In addition, the volume of the GaF6 octahedra also decreases for p4.0 GPa, but remains constant above this pressure. The volume reduction of the GaF6 octahedra is accompanied by an increasing octahedral strain. Isosurfaces of the procrystal electron density are used for visualization of the cubooctahedral voids at different pressures.",

keywords = "compression mechanism, high-pressure, void space",

author = "Jorgensen, {Jens Erik} and Yaroslav Filinchuk and Vladimir Dmitriev",

year = "2017",

month = sep,

day = "1",

doi = "10.1017/S0885715616000701",

language = "English",

volume = "32",

pages = "S69--S73",

journal = "Powder Diffraction",

issn = "0885-7156",

publisher = "Cambridge University Press",

number = "S1",

}

TY - JOUR

T1 - Tilting of semi-rigid GaF6 octahedra in GaF3 at high pressures

AU - Jorgensen, Jens Erik

AU - Filinchuk, Yaroslav

AU - Dmitriev, Vladimir

PY - 2017/9/1

Y1 - 2017/9/1

N2 - The VF3-Type compound GaF3 has been studied by high-pressure angle-dispersive X-ray diffraction in the pressure range from 0.0001 to 10 GPa. The compression mechanism was found to be highly anisotropic. The c-Axis shows little pressure dependence (≈0.4%), but exhibits negative linear compressibility up to ≈3 GPa where it achieves its maximum length. In contrast, the length of the a-Axis is reduced by ≈8.8% at the highest measured pressure and an anomalous reduction in the linear compressibility is observed at 4 GPa. The zero pressure bulk modulus B 0 was determined to B 0 = 28(1) GPa. The compression mechanism of GaF3 is discussed in terms of deformation of an 8/3/c2 sphere-packing model. The volume reduction of GaF3 is mainly achieved through coupled rotations of the GaF6 octahedra within the entire measured pressure range, which reduces the volume of the cubooctahedral voids. In addition, the volume of the GaF6 octahedra also decreases for p4.0 GPa, but remains constant above this pressure. The volume reduction of the GaF6 octahedra is accompanied by an increasing octahedral strain. Isosurfaces of the procrystal electron density are used for visualization of the cubooctahedral voids at different pressures.

AB - The VF3-Type compound GaF3 has been studied by high-pressure angle-dispersive X-ray diffraction in the pressure range from 0.0001 to 10 GPa. The compression mechanism was found to be highly anisotropic. The c-Axis shows little pressure dependence (≈0.4%), but exhibits negative linear compressibility up to ≈3 GPa where it achieves its maximum length. In contrast, the length of the a-Axis is reduced by ≈8.8% at the highest measured pressure and an anomalous reduction in the linear compressibility is observed at 4 GPa. The zero pressure bulk modulus B 0 was determined to B 0 = 28(1) GPa. The compression mechanism of GaF3 is discussed in terms of deformation of an 8/3/c2 sphere-packing model. The volume reduction of GaF3 is mainly achieved through coupled rotations of the GaF6 octahedra within the entire measured pressure range, which reduces the volume of the cubooctahedral voids. In addition, the volume of the GaF6 octahedra also decreases for p4.0 GPa, but remains constant above this pressure. The volume reduction of the GaF6 octahedra is accompanied by an increasing octahedral strain. Isosurfaces of the procrystal electron density are used for visualization of the cubooctahedral voids at different pressures.

KW - compression mechanism

KW - high-pressure

KW - void space

UR - http://www.scopus.com/inward/record.url?scp=85009403757&partnerID=8YFLogxK

U2 - 10.1017/S0885715616000701

DO - 10.1017/S0885715616000701

M3 - Journal article

AN - SCOPUS:85009403757

SN - 0885-7156

VL - 32

SP - S69-S73

JO - Powder Diffraction

JF - Powder Diffraction

IS - S1