Structural, optical, magnetic and dielectric properties of (Cr, Co) co-doped Zn3P2 diluted magnetic semiconductor nanostructures

Cr–Co co-doped zinc phosphide (Zn_3-(x+y)Cr_xCo_yP₂: x, y = 0.01, 0.03, and 0.05) dilute magnetic semiconductor nanoparticles were prepared by solid-state reaction. The effect of Cr–Co dopant concentration on the synthesized samples’ structural, optical, photoluminescence, magnetic, and dielectric properties was examined. From the XRD analysis, it is observed that the prepared samples exhibit a tetragonal structure, and no other Cr–Co-related impurity peaks are observed in the diffraction pattern. The lattice parameters decreased (a = b = 8.133 to 8.000 Å and c = 11.459 to 10.690 Å) with increasing dopant content. SEM images confirmed that the size of the nanoparticles increased and agglomerated with increasing dopant level, in the range of 200 nm. The EDS analysis revealed that the dopant concentration is close to the targeted atomic ratios (Cr and Co). The optical band gap of the Cr–Co-doped nanoparticles increased from 1.397 to 1.413 eV with increasing dopant concentration. With 249 nm excitation wavelengths, photoluminescence (PL) emission peaks were seen in nearly the same wavelength positions. UV, violet, blue, indigo, and green emissions are visible in varied intensities. With increasing Cr–Co concentration, saturation magnetization rises from 0.0702 to 0.2495 emu/g, as confirmed by the VSM study. LCR impedance measurements show a large dielectric constant and loss at low frequencies. AC conductivity is greater in low-frequency regions and lower in high-frequency regions. The formation of spintronic devices is strongly suggested by the findings of the Cr–Co-doped Zn₃P₂ nanoparticles at 1, 3, and 5%.