Large infrared magnetotransmission effect in composite and nano-composite based on Nd0.5Sr0.5MnO3

Abstract

Large negative magnetotransmission effect Δt/t0 = (tH − t0)/t0 (where tH, t0 are the light transmissions with and without magnetic field, respectively) of up to 9% was revealed in composites contained coarse-grained and nano-powders of Nd0.5Sr0.5MnO3 in the infrared (IR) range near the Curie temperature in magnetic field H = 8 kOe. The optical density spectra and magnetotransmission effect of the composites are discussed in the context of the polar centers phase model. In the nano-powder composite, the significant magnetotransmission of ∼7% takes place in wide temperature region far below TC. This fact is explained by the existence of the localized charge carriers and spin disorder at the nano-particles surface. An applied magnetic field reduces spin disorder and the localization of charge carriers resulting in negative magnetotransmission effect. Two magnetic phase transitions and phase separation in Nd0.5Sr0.5MnO3 promote the large magnetotransmission effect in a wide temperature range. The Nd0.5Sr0.5MnO3 nano-powder composite is a promising material for magnetooptical devices with a wide working temperature range.