We have studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba,K)(Zn,Mn)2As2 through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. We detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of ≲5 \AA, resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment of Mn spins along the crystallographic c-axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. We discuss these results in the context of other experiments and theoretical studies on this system.
@article{arxiv.1608.02684,
title = {Local atomic and magnetic structure of dilute magnetic semiconductor (Ba,K)(Zn,Mn)$_2$As$_2$},
author = {Benjamin A. Frandsen and Zizhou Gong and Maxwell Terban and Soham Banerjee and Bijuan Chen and Changqing Jin and Mikhail Feygenson and Yasutomo J. Uemura and Simon J. L. Billinge},
journal= {arXiv preprint arXiv:1608.02684},
year = {2016}
}