TY - JOUR
T1 - Pressure-induced structural changes in the superconductor (Nd1-xSrx (Nd1-yCey) CuO4-z. A neutron diffraction study
AU - Izumi, F.
AU - Jorgensen, J. D.
AU - Lightfoot, P.
AU - Pei, Shiyou
AU - Yamada, Y.
AU - Takayama-Muromachi, E.
AU - Matsumoto, T.
PY - 1990/12/1
Y1 - 1990/12/1
N2 - The crystal structure of (Nd0.59Sr0.41) (Nd0.73Ce0.27)CuO4-z (z≈0.4) was investigated by means of TOF neutron powder diffraction at six hydrostatic pressure up to 0.637 GPa with a He gas pressure cell. The superconducting transition temperature of this oxide has a positive pressure coefficient, dTc/dP, of 4.0 K GPa-1. As the pressure is increased, the a and c lattice parameters of its tetragonal cell both decrease linearly, which leads to a similar decrease in the length of a Cu-O (1) bond within a CuO2 sheet. Increasing pressure also decrease the distance Cu and axial O(2) atoms at a similar rate. Unfortunately, larger uncertainties for the Cu-O(2) bond length make a quantitative comparison difficult. It is clear, however, that no pronounced changes are observed in individual Cu-O bond lengths when compared with the overall cell compression. We conclude that an understanding of the pressure effect on Tc must be gained by considering pressure-induced changes in the overall structure rather than focussing attention on a single Cu-O bond.
AB - The crystal structure of (Nd0.59Sr0.41) (Nd0.73Ce0.27)CuO4-z (z≈0.4) was investigated by means of TOF neutron powder diffraction at six hydrostatic pressure up to 0.637 GPa with a He gas pressure cell. The superconducting transition temperature of this oxide has a positive pressure coefficient, dTc/dP, of 4.0 K GPa-1. As the pressure is increased, the a and c lattice parameters of its tetragonal cell both decrease linearly, which leads to a similar decrease in the length of a Cu-O (1) bond within a CuO2 sheet. Increasing pressure also decrease the distance Cu and axial O(2) atoms at a similar rate. Unfortunately, larger uncertainties for the Cu-O(2) bond length make a quantitative comparison difficult. It is clear, however, that no pronounced changes are observed in individual Cu-O bond lengths when compared with the overall cell compression. We conclude that an understanding of the pressure effect on Tc must be gained by considering pressure-induced changes in the overall structure rather than focussing attention on a single Cu-O bond.
UR - http://www.scopus.com/inward/record.url?scp=0025631478&partnerID=8YFLogxK
U2 - 10.1016/0921-4534(90)90656-Y
DO - 10.1016/0921-4534(90)90656-Y
M3 - Article
AN - SCOPUS:0025631478
SN - 0921-4534
VL - 172
SP - 166
EP - 174
JO - Physica C: Superconductivity and its applications
JF - Physica C: Superconductivity and its applications
IS - 1-2
ER -