Mn5Ge3 thin films epitaxially grown on Ge(111) exhibit metallic conductivity and strong ferromagnetism up to about 300 K. Recent experiments suggest a non-collinear spin structure. In order to gain deep insights into the magnetic structure of this compound, we have performed fully unconstrained ab-initio pseudopotential calculations within density functional theory, investigating the different magnetic states corresponding to Collinear (C) and Non-Collinear (NC) spin configurations. We focus on their relative stability under pressure and strain field. Under pressure, the C and NC configurations are degenerate, suggesting the possible occurrence of accidental magnetic degeneracy also in Mn5Ge3 real samples. We found a continuous transition from a ferromagnetic C low-spin state at small volumes to a NC high-spin state at higher volumes. Remarkably, the degeneracy is definitely removed under the effect of uniaxial strain: in particular, NC spin configurations is favoured under tensile uniaxial strain.
@article{arxiv.cond-mat/0608176,
title = {Non-collinear Magnetic states of Mn5Ge3 compound},
author = {A. Stroppa and M. Peressi},
journal= {arXiv preprint arXiv:cond-mat/0608176},
year = {2015}
}
Comments
13 pages,2 Tables, 5 figures, Revised Version, Materials Science in Semiconductor Processing (in press)