High-pressure behavior and thermoelastic properties of niobium studied by in situ x-ray diffraction

Journal Article · Mon Jul 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4887436· OSTI ID:22306167

Zou, Yongtao; Li, Baosheng ^[1]; Qi, Xintong ^[2]; Wang, Xuebing; Chen, Ting ^[3]; Li, Xuefei ^[1]; Welch, David ^[2]

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1. Mineral Physics Institute, State University of New York, Stony Brook, New York 11794 (United States)
2. Department of Materials Science and Engineering, State University of New York, Stony Brook, New York 11794 (United States)
3. Department of Geosciences, State University of New York, Stony Brook, New York 11794 (United States)

In situ synchrotron energy dispersive x-ray diffraction (XRD) experiments on Nb have been conducted at pressures up to 6.4 GPa and temperatures up to 1073 K. From the pressure-volume-temperature measurements, thermoelastic parameters were derived for the first time for Nb based on the thermal pressure (ΔP{sub th}) equation of state (EOS), modified high-T Birch-Murnaghan EOS, and Mie-Grüneisen-Debye EOS. With the pressure derivative of the bulk modulus K{sub T}{sup ´} fixed at 4.0, we obtained the ambient isothermal bulk modulus K{sub T0}=174(5) GPa, the temperature derivative of bulk modulus at constant pressure (∂K{sub T}/∂T){sub P}=-0.060(8) GPa K⁻¹ and at constant volume (∂K{sub T}/∂T){sub V}=-0.046(8) GPa K⁻¹, the volumetric thermal expansivity α{sub T}(T)=2.3(3)×10⁻⁵+0.3(2)×10⁻⁸T (K⁻¹), as well as the pressure dependence of thermal expansion (∂α/∂P){sub T}=(₋2.0±0.4)×10⁻⁶ K⁻¹ GPa⁻¹. Fitting the present data to the Mie-Grüneisen-Debye EOS with Debye temperature Θ₀=276.6 K gives γ₀=1.27(8) and K{sub T0}=171(3) GPa at a fixed value of q=3.0. The ambient isothermal bulk modulus and Grüneisen parameter derived from this work are comparable to previously reported values from both experimental and theoretical studies. An in situ high-resolution, angle dispersive XRD study on Nb did not indicate any anomalous behavior related to pressure-induced electronic topological transitions at ~5 GPa as has been reported previously.

• OSTI ID: 22306167
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DEBYE TEMPERATURE
EQUATIONS OF STATE
NIOBIUM
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
RESOLUTION
SYNCHROTRON RADIATION
TEMPERATURE MEASUREMENT
THERMAL EXPANSION
THERMOELASTICITY
X-RAY DIFFRACTION