Ferromagnetic ordering in nanostructured Mn-doped InP

We report the observation of ferromagnetic ordering at 25K in a diluted magnetic semiconductor (DMS) nanoparticle system: In0.9Mn0.1P, sized 3nm. These particles were synthesized using a novel nanochemical technique without using any external surfactant. Structural and elemental characterizations established the occurrence of the zinc-blende phase of the DMS without any separate or induced impurity phase. A robust onset of ferromagnetic order is observed in magnetization measurements at around 25K with blocked state behavior below 15K characteristic of magnetic nanoparticles. The system shows strong frequency dependence of the susceptibility, similar to the behavior observed for spin glasses. Reversible transverse susceptibility experiments done using a resonant radio-frequency (rf) method reveal a strong temperature-dependent effective anisotropy.