TY - JOUR

T1 - Thermal expansion of superconduct

AU - Asahi, T.

AU - Suzuki, H.

AU - Nakamura, M.

AU - Takano, H.

AU - Kobayashi, J.

N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

PY - 1997

Y1 - 1997

N2 - Temperature dependences of thermal strains of superconducting (Formula presented)(Formula presented)(Formula presented)(Formula presented) were measured by using the two-dimensional reciprocal-lattice method of x-ray diffraction in the temperature range between 15 and 300 K. Accuracies of measuring the lattice strains attained 1.6×(Formula presented). Very small anomalies of the lattice constants and lattice volume took place at (Formula presented) of the transition point. They were caused by definite discontinuities of the thermal-expansion coefficients. Using previously reported values of specific heat and isotropic compressibility a nearly temperature-independent equivalent Grüneisen parameter (Formula presented) was derived as 0.89±0.11. From the extrapolation of the lattice volume of the high-temperature phase into the superconducting temperature region, additive lattice strains were found to appear spontaneously in the superconducting phase. From this fact it was concluded that a structural phase transition of the second order took place with the onset of superconductivity.

AB - Temperature dependences of thermal strains of superconducting (Formula presented)(Formula presented)(Formula presented)(Formula presented) were measured by using the two-dimensional reciprocal-lattice method of x-ray diffraction in the temperature range between 15 and 300 K. Accuracies of measuring the lattice strains attained 1.6×(Formula presented). Very small anomalies of the lattice constants and lattice volume took place at (Formula presented) of the transition point. They were caused by definite discontinuities of the thermal-expansion coefficients. Using previously reported values of specific heat and isotropic compressibility a nearly temperature-independent equivalent Grüneisen parameter (Formula presented) was derived as 0.89±0.11. From the extrapolation of the lattice volume of the high-temperature phase into the superconducting temperature region, additive lattice strains were found to appear spontaneously in the superconducting phase. From this fact it was concluded that a structural phase transition of the second order took place with the onset of superconductivity.

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U2 - 10.1103/PhysRevB.55.9125

DO - 10.1103/PhysRevB.55.9125

M3 - Article

AN - SCOPUS:0013189537

SN - 1098-0121

VL - 55

SP - 9125

EP - 9129

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 14

ER -