Structural, surface, magnetic, and dielectric properties of Ni0.3Cu0.3Zn0.4Fe1.4Cr0.6O4 spinel ferrite nanocrystals prepared by sol-gel auto combustion route

Multi-metal spinel ferrite nanocrystals of Ni0.3Cu0.3Zn0.4Fe1.4Cr0.6O4 was synthesized by sol-gel auto-combustion route. Structural, magnetic, and dielectric properties of the prepared nanocrystals were affected by different calcination temperatures. The values of crystallite size 30.9-51.1 nm, lattice strain 3.68 x 10- 3-2.21 x 10-3, and dislocation density 1.046 x 10- 3-0.382 x 10- 31/nm2 were estimated for the prepared NPs. The magnitudes of saturation magnetization 20.83-33.37 emu/g, retentivity 1.18-1.98 emu/g, coercivity 30.56-35.29 Oe, and magnetic anisotropy 3.531 x 103-6.133 x 103 emu/cm3 of the prepared NPs were evaluated under the applied magnetic field of (17kOe). The dielectric constant magnitudes 6810.41, 5.85 x 104, 5.91 x 104, and 5.21 x 104 were reported for non-calcinated NPs (ST), calcinated CT4 NPs at 400 degrees C, CT6 NPs at 600 degrees C, and CT8 NPs at 800 degrees C, respectively at low-frequency range. The dielectric loss magnitudes 2210.84, 3.23 x 10 5, 3.10 x 10 5, and 3.13 x 10 5 were reported for ST, CT4, CT6, and CT8 NPs at the low-frequency range, respectively. The conductivity values 2.46 x 10-3, 361.79 x 10-3, 372.49 x 10-3, and 342.63 x 10-3 S/m for ST, CT4, CT6 and CT8 at low frequency range, respectively. Impedance values 4250, 95, 81, and 80 (Ohm) were recorded ST, CT4, CT6, and CT8 NPs at low-frequency range, respectively. The prepared NPs of Ni0.3Cu0.3Zn0.4Fe1.4Cr0.6O4 can be used for the fabrication of good-quality capacitors, recording systems, high-frequency devices and multilayer chip inductor applications.