Hunt for the Hidden Order in the Mn3Al2Ge3O12 Garnet

We seek to explore the nature of the spin-spin correlations in the manganese garnet Mn3Al2Ge3O12 by measuring the diffuse scattering signal at just above its Neel point. We have prepared and characterised a large single crystal of Mn3Al2Ge3O12, providing a unique chance to investigate the spin-spin correlations in detail and hunt for the multipolar "hidden order" of 10-spin loops previously found in Gd garnets Gd3Ga5O12 (GGG) and Gd3Al5O12 (GAG). The crystal structure of Mn3Al2Ge3O12 is identical to them with magnetic ions Mn2+ (L=0), rendering it the closest compound to the Gd garnets in its magnetic properties. The constituent magnetic Mn2+ is advantageous, as its neutron absorption is much lower than that of Gd. We propose to investigate the magnetic diffuse scattering of a phase pure single crystal sample of Mn3Al2Ge3O12 and its temperature dependence.