LAUSR

Abstract CoPt nanoparticles (NPs) were synthesized by sol-gel route from metal chloride precursors. NPs annealed at 800 °C under hydrogen atmosphere which reveals the formation of bimetallic L10 face centered tetragonal (FCT) CoPt alloy NPs confirmed by XRD study and selected area diffraction (SAED) pattern. Here the magnetic properties were investigated from room temperature down to 77 K by vibrating sample magnetometer (VSM). Magnetic measurement revealed that NPs possess ferromagnetic property with a high coercivity 143.24 kAm−1 and remanence because of high anisotropic behavior. However, low temperature magnetization shows an anomalous antiferromagnetic nature of CoPt NPs due to spin canting effect. The band structure and electronic density of states (DOS) calculation indicate the metallic nature of the L10 FCT CoPt NPs. The magnetic moment arises due to electronic spin polarization which is found to be 2.38 μB, calculated using spin density of states (SDOS).