We have investigated structural and magnetic phase transitions under high pressures in a quaternary rare earth transition metal arsenide oxide NdCoAsO compound that is isostructural to high temperature superconductor NdFeAsO. Four-probe electrical resistance measurements carried out in a designer diamond anvil cell show that the ferromagnetic Curie temperature and anti-ferromagnetic Neel temperature increase with an increase in pressure. High pressure x-ray diffraction studies using a synchrotron source show a structural phase transition from a tetragonal phase to a new crystallographic phase at a pressure of 23 GPa at 300 K. The NdCoAsO sample remained anti-ferromagnetic and non-superconducting to temperatures down to 10 K and to the highest pressure achieved in this experiment of 53 GPa. A P-T phase diagram for NdCoAsO is presented to a pressure of 53 GPa and low temperatures of 10 K.
@article{arxiv.1104.3172,
title = {Structural and Magnetic Phase Transitions in NdCoAsO under High Pressures},
author = {Walter Uhoya and Georgiy M. Tsoi and Yogesh K. Vohra and Michael A. McGuire and Athena S. Sefat and Brian C. Sales and David Mandrus and Samuel T. Weir},
journal= {arXiv preprint arXiv:1104.3172},
year = {2011}
}
Comments
6 pages, 6 figures, available online at stacks.iop.org/JPhysCM/22/185702