Influence of particle size on spin switching properties and magnetoelectric coupling in SmFeO3

Controlling the magnetic properties of a material is of great importance for spintronics and magnetoelastic devices. We studied effect of reduced particle size on structural, dielectric and magnetic properties of SmFeO3 nanoparticles prepared by co-precipitation method (SFO-C) and by combustion (SFO-S). Reduced particle size modified interesting magnetic features of SmFeO3. Temperature dependent magnetic study reveal significant enhancement in magnetization reversal temperature and drop in spin reorientation transition temperature. The signature of spin reorientation transition for SFO-C (similar to 300 nm) is marked at similar to 450 K, while this temperature drops down to similar to 400 K for SFO-C (similar to 50 nm). The magnetization reversal temperature is achieved at 30.5 K for SFO-C, much higher than 4 K, reported for the single crystal and bulk SmFeO3. The presence significant anomalies in the temperature dependent dielectric behavior of SmFeO3 samples across spin reorientation transition temperature indicate magneto electrical coupling. Strong exchange-bias effect is observed at low temperature for both the samples. The lowering of spin reorientation/switching transition temperature due to reduction in particle size and the signature of magnetoelectric coupling at this temperature are useful for room temperature devices. The observed experimental results establish that the spin switching properties of SmFeO3 can be modified for practical applications in devices.