Abstract
We report the characterisation of natural samples of the cubic pyrite mineral MnS2 using very high resolution synchrotron X-ray diffraction techniques. At low temperatures we find a new low temperature polymorph, which results from coupling between magnetic and lattice degrees of freedom. Below the magnetic ordering temperature TN = 48 K, we detect a pseudo-tetragonal distortion with a tiny c/a ratio of 1.0006. The structure can be refined in the space group P bca The symmetry lowering reduces magnetic frustration in the fcc Mn2+ lattice and is likely responsible for the previously reported lock-in of the magnetic propagation vector. This behaviour is similar to the frustration driven symmetry breaking reported in other three-dimensional Heisenberg magnets like the chromate spinels.
To download the article click on the link below:
0 Comments