Annealing effects on the microstructure and properties of Y(Ni,Mn)O 3 thin films

Abstract

Epitaxially c-axis oriented thin films of YNi x Mn 1− x O 3 (YNMO), x = 0.33 and 0.5, were grown on (1 0 0) SrTiO 3 substrates by pulsed laser-ablated deposition technique. High temperature oxygen annealing shows a large improvement in the ferromagnetic transition temperature T c for the film with x(Ni) = 0.33 while only a slight increase in T c occurs for the x(Ni) = 0.5 film. We suggest that such increase in T c is largely associated with microstructural changes induced by the thermal annealing. In order to optimize the magnetic properties of the YNMO films, it is necessary to control the initial growth conditions so as to have a microstructure of well-connected grains of uniform size.