Investigations of magnetic and dielectric properties of cupric oxide nanoparticles

Cupric oxide nanoparticles of ∼8–10 nm width and 40–45 nm length self assembled as large particles ∼1–1.5 μm have been investigated, in the 10–325 K temperature range, using magnetic and dielectric measurements. In magnetic measurements a single broad peak at ∼230 K in a zero field cooled sample has been observed. Coercivity, in magnetization measurements at 10 K, suggests that the nanoparticles are core-shell type particles with an antiferromagnetic core and a ferromagnetic shell. Dielectric measurements, at various frequencies from 3.7 Hz to 949 kHz, exhibit a sharp peak at 284 K followed by weak anomalies around 213 and 230 K.

Research highlights► 8 nm width oriented nanoparticles self assembled as large particles ∼1 μm. ► Enhanced coercivity with exchange bias in 10 K magnetic measurements. ► Sharp peak in dielectric measurements at 284 K. ► Are core-shell type with an antiferromagnetic core and a ferromagnetic shell.