Abstract
Structural, magnetic and terahertz emission properties of Bi(Fe1-xMnx)O3 (0⩽x⩽0.5) thin films of various thicknesses were studied. A transition from coherently strained structure to relaxed structure at a film thickness (t) of ∼80–90 nm occurs only for x<0.2. It is shown that terahertz-emission efficiency is not deteriorated with increasing Mn-doping (x). The magnetic moment of thin films (t⩽85 nm) exhibits only a weak enhancement with increasing x —a feature suggesting that Mn-doping is ineffective in inducing ferromagnetism in BiFeO3. The thicker films (t⩾150 nm), on the contrary, possess larger magnetic moment which evidently arises from the segregated magnetic MnFe2O4 phase.