Effect of A-site ordering on IR absorption and magnetotransmission in PrBaMn2O6 double manganite

For double manganites PrBaMn2O6 with different degree of A-site ordering, magnetic and optical properties in near-IR range were studied. Full ordered manganite is characterized by antiferromagnetic state at low temperatures; magnetic phase transition from antiferromagnetic to ferromagnetic state occurs near T-N = 262 K and to paramagnetic state near T-C = 305 K. Partially disordered manganite consists of few fractions with different state of A-site ordering and shows the transition from ferromagnetic state to paramagnetic one at 190 K. For disordered manganite weak ferromagnetic contribution is observed below 130 K. The optical density spectra and the temperature dependences of light transmission indicate a change in behavior of the charge carrier system (metal-insulator transition) near the magnetic phase transitions. The magnetotransmission effect was measured for the first time in double manganites PrBaMn2O6. Spectral dependence of magnetotransmission lets associate this effect with an increase in the fraction of delocalized charge carriers when a magnetic field is applied.