Magnetism and infrared magnetotransmission of Nd0.5Sr0.5MnO3 manganite in nanostate

The magnetic properties of nanopowders of Nd0.5Sr0.5MnO3 manganite, obtained by ball milling method, and IR magnetotransmission (the relative change in transmission of infrared radiation in a magnetic field) of composites based on the nanopowders are studied and compared with properties of Nd0.5Sr0.5MnO3 single crystal and coarse grain powder. The strong decrease of the magnetization at transformation of the single crystal to coarse grain powder is associated with the martensitic nature of the charge-ordered state (CO), TCO∼150 K. With a further decrease of particles size the magnetization decreases sharply above 150 K and is less significant in the region below 150 K, where a plateau in temperature dependence of magnetization and magnetotransmission takes place. The plateau is explained by modification of the manganite properties at milling and associated with competition of the ferromagnetic and antiferromagnetic contributions in cores and surface of the nanoparticles and change in the degree of localization of charge carriers in the magnetic field. The high value of the magnetotransmission (up to 9%) in a wide temperature range for nanocomposites are promising for creation of magnetically controlled infrared optoelectronic devices.