Preparation and properties of inverse perovskite Mn₃GaN thin films and heterostructures

Thin films and heterostructures of Mn₃GaN with an inverse perovskite structure were grown epitaxially on SrTiO₃ (001) and (La_0.18Sr_0.82)(Al_0.59Ta_0.41)O₃ (001) (LSAT) substrates by ion beam sputtering, and their structural and electrical properties have been investigated. Mn₃GaN epitaxial thin films showed metallic behavior of temperature-dependent resistivity with a small maximum at 290-340 K. The maximum resistivity could be attributed to the magnetic transition from antiferromagnetism to paramagnetism. It has been found that epitaxial heterostructures formed by ferroelectric Ba_0.7Sr_0.3TiO₃ and Mn₃GaN layers exhibit a large magnetocapacitance effect of more than 2000% in an applied magnetic filed of 1.5 T.