Is Y1Ba2Cu3O7 stiff or soft?

1990 ◽  
Vol 5 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Hassel Ledbetter ◽  
Ming Lei
Keyword(s):  
High Pressure ◽  
Metal Oxide ◽  
Physical Properties ◽  
Bulk Modulus ◽  
Model Calculation ◽  
Ionic Crystal ◽  
Oxide Superconductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Model

Using several measured and calculated physical properties, we argue that the high-Tc metal-oxide superconductor Y1Ba2Cu3O7 is elastically soft compared with BaTiO3 or SrTiO3. We conclude that the bulk modulus equals approximately 107 GPa, despite several high-pressure x-ray diffraction studies that report values up to approximately 200 GPa. Part of the argument uses an ionic-crystal-model calculation of the bulk modulus.

A high-pressure study of HfC and nano-crystalline TiC by X-ray diffraction and density functional theory calculations

2020 ◽  
Vol 34 (34) ◽  
pp. 2050393
Author(s):  
Lun Xiong ◽  
Bin Li ◽  
Bi Liang ◽  
Jinxia Zhu ◽  
Hong Yi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Nano Crystalline

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus [Formula: see text] GPa with [Formula: see text] of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is [Formula: see text] GPa with [Formula: see text].

Elastic Properties of Calcium Oxide Perovskites

2002 ◽  
Vol 718 ◽  
Author(s):  
Nancy L. Ross ◽  
Ross J. Angel ◽  
Jennifer Kung ◽  
Tracey D. Chaplin
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Calcium Oxide ◽  
Specific Volume ◽  
Equations Of State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Threefold Increase ◽  
Volume Relationship ◽  
Brownmillerite Structure

AbstractThe equations of state and axial moduli of the CaBO3 perovskites (B=Zr,Sn,Ti,Ge) and CaFeO2.5 with the brownmillerite structure have been determined using high-pressure, singlecrystal X-ray diffraction. The bulk modulus-specific volume relationship for the Ca-perovskites is nonlinear, with CaSnO3 and CaZrO3 displaying anomalous stiffening (higher bulk moduli) than previously reported and predicted [1,2]. The axial moduli of the a- and c-axes decrease steadily by ∼30% from the least-distorted of the Pbnm perovskites, CaGeO3, to the most distorted, CaZrO3, while the b-axis shows little change. The net result is a threefold increase in the anisotropy of the axial moduli of CaSnO3 and CaZrO3 (∼21%) relative to CaGeO3 and CaTiO3 (∼4-8%). The bulk modulus of CaFeO2.5 falls significantly below the trend for the stoichiometric perovskites. The introduction of 1/6 vacancies on the oxygen positions softens the perovskite structure by 25%.

Compressibility of the high-pressure polymorph of AlOOH to 17 GPa

2009 ◽  
Vol 73 (3) ◽  
pp. 479-485 ◽  
Author(s):  
A. Suzuki
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Neutron Diffraction ◽  
Bulk Modulus ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
X Ray ◽  
A Value

AbstractThe equation of state of δ-AlOOH was investigated using powder X-ray diffraction up to 17 GPa. Measurement of the volume at 300 K gave a value of the bulk modulus of K0 = 124(2) GPa, whereas its pressure derivative was K’ = 13.5(7). The b axis of the unit cell is more compressible than the a and c axes – in agreement with a neutron diffraction study at high pressure by Sano-Furukawa et al. (2008). Measurements presented here show that δ-AlOOH has a compressibility 200% higher than in the previously reported equation of state by Vanpeteghem et al. (2002).

X-ray diffraction study of HgBa2CuO4+δ at high pressures

1997 ◽  
Vol 12 (2) ◽  
pp. 106-112
Author(s):  
Eduardo J. Gonzalez ◽  
Winnie Wong-Ng ◽  
Gasper J. Piermarini ◽  
Christian Wolters ◽  
Justin Schwartz
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Pressure Range ◽  
High Pressures ◽  
Anisotropy Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anisotropic Elastic ◽  
High Pressure Study

An in situ high pressure study using energy dispersive X-ray diffraction has been carried out on the polycrystalline high-Tc superconductor, HgBa2CuO4+δ (Hg-1201), to study its phase stability under pressure and also to measure its compressibility and bulk modulus. No evidence of pressure-induced polymorphism was found in the pressure range investigated, i.e., from 0.1 MPa (1 atm) to 5 GPa. The compound exhibited anisotropic elastic properties. The axial compressibility along the c axis was measured to be (3.96±0.35)×10−3GPa−1 and along the a axis (3.42±0.13)×10−3GPa−1, corresponding to an anisotropy ratio of 1.16±0.11. The bulk modulus was determined to be (94.7±4.2) GPa and, assuming a Poisson's ratio of 0.2, Young's modulus was estimated to be (170±8) GPa.

scholarly journals High Pressure Brillouin Spectroscopy and X-ray Diffraction of Cerium Dioxide

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3683
Author(s):  
Mungo Frost ◽  
John D. Lazarz ◽  
Abraham L. Levitan ◽  
Vitali B. Prakapenka ◽  
Peihao Sun ◽  
...  
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Cerium Dioxide ◽  
Room Temperature ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
Brillouin Spectroscopy ◽  
X Ray ◽  
Nanocrystalline Cerium Dioxide ◽  
Acoustic Velocities

Simultaneous high-pressure Brillouin spectroscopy and powder X-ray diffraction of cerium dioxide powders are presented at room temperature to a pressure of 45 GPa. Micro- and nanocrystalline powders are studied and the density, acoustic velocities and elastic moduli determined. In contrast to recent reports of anomalous compressibility and strength in nanocrystalline cerium dioxide, the acoustic velocities are found to be insensitive to grain size and enhanced strength is not observed in nanocrystalline CeO2. Discrepancies in the bulk moduli derived from Brillouin and powder X-ray diffraction studies suggest that the properties of CeO2 are sensitive to the hydrostaticity of its environment. Our Brillouin data give the shear modulus, G0 = 63 (3) GPa, and adiabatic bulk modulus, KS0 = 142 (9) GPa, which is considerably lower than the isothermal bulk modulus, KT0∼ 230 GPa, determined by high-pressure X-ray diffraction experiments.

scholarly journals The High-Pressure Structural Evolution of Olivine along the Forsterite–Fayalite Join

Minerals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 790 ◽  
Author(s):  
Martha G. Pamato ◽  
Fabrizio Nestola ◽  
Davide Novella ◽  
Joseph R. Smyth ◽  
Daria Pasqual ◽  
...  
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Room Temperature ◽  
Structural Evolution ◽  
X Ray Diffraction ◽  
Crystallographic Site ◽  
X Ray ◽  
Fe Content ◽  
Structural Mechanisms ◽  
Polyhedral Volumes

Structural refinements from single-crystal X-ray diffraction data are reported for olivine with a composition of Fo100 (forsterite Mg2SiO4, synthetic), Fo80 and Fo62 (~Mg1.6Fe0.4SiO4 and ~Mg1.24Fe0.76SiO4, both natural) at room temperature and high pressure to ~8 GPa. The new results, along with data from the literature on Fo0 (fayalite Fe2SiO4), were used to investigate the previously reported structural mechanisms which caused small variations of olivine bulk modulus with increasing Fe content. For all the investigated compositions, the M2 crystallographic site, with its bonding configuration and its larger polyhedral volume, was observed to control the compression mechanisms in olivine. From Fo100 to Fo0, the compression rates for M2–O and M1–O bond lengths were observed to control the relative polyhedral volumes, resulting in a less-compressible M1O6 polyhedral volume, likely causing the slight increase in bulk modulus with increasing Fe content.

Experimental determination of bulk modulus of 14Å tobermorite using high pressure synchrotron X-ray diffraction

2012 ◽  
Vol 42 (2) ◽  
pp. 397-403 ◽  
Author(s):  
Jae Eun Oh ◽  
Simon M. Clark ◽  
Hans-Rudolf Wenk ◽  
Paulo J.M. Monteiro
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Experimental Determination ◽  
X Ray Diffraction ◽  
X Ray

HIGH PRESSURE-HIGH TEMPERATURE ELECTRICAL RESISTIVITY STUDIES ON Nd0.9Ca0.1Ba2Cu3O7-δ

2006 ◽  
Vol 20 (29) ◽  
pp. 4885-4890
Author(s):  
R. SELVA VENNILA ◽  
S. REZA GHORBANI ◽  
N. VICTOR JAYA
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Bulk Modulus ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Heating Coil ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Electrical Resistivity Study

High pressure-high temperature electrical resistivity study on composition-controlled Nd 0.9 Ca 0.1 Ba 2 Cu 3 O 7-δ high T c superconductor (HTSC) is carried out by a four-probe technique using Bridgman anvils. A simple heating coil arrangement is used for heating the samples. Electrical resistivity behavior under pressure (up to a maximum of 8 GPa) at various temperatures (up to a maximum of 523 K) were studied and reported in this paper. Simulation of energy dispersive X-ray diffraction confirms substitution of calcium at the Nd site of Nd -123. Variation of the electrical resistivity under pressure is compared with that of the structural changes and the bulk modulus was determined.

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