Neutron and x-ray diffraction measurements are presented for powders and single crystals of CaCo{1.86}As2. The crystal structure is a collapsed-tetragonal ThCr2Si2-type structure as previously reported, but with 7(1)% vacancies on the Co sites corresponding to the composition CaCo{1.86(2)}As2. The thermal expansion coefficients for both the a- and c-axes are positive from 10 to 300 K. Neutron diffraction measurements on single crystals demonstrate the onset of A-type collinear antiferromagnetic order below the Neel temperature TN = 52(1) K with the ordered moments directed along the tetragonal c-axis, aligned ferromagnetically in the ab-plane and antiferromagnetically stacked along the c-axis.
@article{arxiv.1310.2587,
title = {Crystal and Magnetic Structure of CaCo{1.86}As2 Studied by X-ray and Neutron Diffraction},
author = {D. G. Quirinale and V. K. Anand and M. G. Kim and Abhishek Pandey and A. Huq and P. W. Stephens and T. W. Heitmann and A. Kreyssig and R. J. McQueeney and D. C. Johnston and A. I. Goldman},
journal= {arXiv preprint arXiv:1310.2587},
year = {2014}
}
Comments
8 pages, 5 figures, 2 tables; submitted to Phys. Rev. B