Shear strain in Nd0.5Ca0.5MnO3 at high pressures.
High-pressure x-ray powder diffraction has been measured on the half doped rare earth manganite Nd0.5Ca0.5MnO3 up to a pressure of 15 GPa. We report the presence of a quantifiable amount of shear distortion of the MnO6 octahedra in Nd0.5Ca0.5MnO3 at high pressures. The lattice strain of Nd0.5Ca0.5MnO3 is minimal at a crossover pressure of p* approximately 7 GPa, with the same lattice strain above and below this pressure achieved by shear and Jahn-Teller-type distortions, respectively. The increase in shear strain with increasing pressure provides a mechanism for the insulating behavior of manganites at high pressures that has not been considered before.
Arulraj
Anthony
A
Laboratory of Crystallography, University of Bayreuth, D-95440 Bayreuth, Germany. anthony.arulraj@uni-bayreuth.de
Dinnebier
Robert E
RE
Carlson
Stefan
S
Hanfland
Michael
M
van Smaalen
Sander
S