Antiferromagnetic properties of MnGa2Se4-α
Year: 1982
Type: article
Abstract: Single crystals of the ternary tetragonal manganese chalcogenide MnGa 2Se4-α have been grown by the vapour phase transport technique. Magnetic susceptibility and magnetization measurements establish that MnGa2Se4-α orders antiferromagnetically below 7 K. The Curie-Weiss temperature is found to be - 23 ± 2 K; the effective magnetic moment per Mn of 6.0 ± 0.1 μB is consistent with Mn 2+ ions. The value of the Néel temperature as obtained by specific heat data is TN = 6.4 ± 0.1 K. The transition is second order with an entropy well accounted for by Mn2+ ions. Both the temperature dependence of the EPR linewidth and the specific heat data show that short-range order persists at temperatures much higher than TN. Powder neutron diffraction data have been collected at several temperatures; they are consistent with previous X-ray studies and further establish that the cations are well ordered on the tetrahedral sites; several magnetic reflections are found on the low-temperature spectra; a possible type of magnetic ordering is proposed. Exchange integrals, involving super-superexchange through Mn-Se-Ga-Se-Mn bonds are estimated to be in the range 0.1 K to 0.5 K.
Source: Journal de physique
Authors: R. Rimet, C. Schlenker, D. Fruchart
Institution: Centre National de la Recherche Scientifique
Language: French
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2004493907