The impact of solvent tanδ on the magnetic characteristics of nanostructured NiZn-ferrite film deposited by microwave-assisted solvothermal technique

Nanostructured Ni-Zn ferrite (NZF) thin films, deposited by a CMOS-compatible microwave-assisted solvothermal deposition (MAS-D) process, exhibit ‘far-from-equilibrium’ distribution of cations in the spinel structure, and thus, exciting magnetic properties. Solvents with different dielectric loss-tangents, such as ethanol (tanδ≈0.94), 1-decanol (tanδ≈0.1), benzyl alcohol (tanδ≈0.67), were mixed five judiciously-chosen proportions – ED35 (ethanol:1-decanol=3:5; tanδ≈0.51), ED33 (tanδ≈0.63), EB25 (tanδ≈0.66), EB35 (tanδ≈0.70), EB33 (tanδ≈0.74) to study impact effective tanδ on cation occupancy nature magnetization resulting films. The maximum temperature attained during microwave irradiation (Tmax) heating rate (∆T/trise) increase solvent mixture increases, which effect leads Ni atoms migrate towards equilibrium lattice sites. Unlike bulk NZF, where all occupy octahedral sites (B-sites), films reported here just 28% B-sites at best when from precursor solution EB25. At room are superparamagnetic, while moment (MS=100 emu/cc) is observed film highest % B-sites. Thermoremanent (TRM) samples studied compared. Very high anisotropy constants (Keff=140 kJ/m3), two-orders-of magnitude-higher inter-particle dipole (Edipole≈8×10-20 J @300 K) prepared rather than signifying potential for tailoring properties choice solvents MAS-D process.