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We have studied the structural, electronic and magnetic properties of pulsed laser deposited thin films of Ni 1− x Cr x Fe 2 O 4 ( x =0.02 and 0.05) on Si (111) and Si (100) substrates. The films reveal single phase, polycrystalline structure with larger grain size on Si (111) substrate than that on Si (100) substrate. Contrary to the expected inverse spinel structure, x-ray photoemission (XPS) studies reveal the mixed spinel structure. XPS results suggest that Ni and Fe ions exist in 2+ and 3+ states, respectively, and they exist in tetrahedral as well as octahedral sites. The deviation from the inverse spinel leads to modified magnetic properties. It is observed that saturation magnetization drastically drops compared to the expected saturation value for inverse spinel structure. Strain in the films and lattice distortion produced by the Cr doping also appear to influence the magnetic properties. [ABSTRACT FROM AUTHOR]

Structural and magnetic response of Ni 1-x Cr x Fe 2 O 4 (x = 0 and 0.05) are presented using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and SQUID magnetometer. The single phase of both the compositions is confirmed using Rietveld refinement method. The absence of any impurity is further cinched using structural sensitive techniques, namely FTIR and Raman spectroscopy. Interestingly, a pinched shaped M − H behaviour is observed for the Cr doped ferrite. In addition, we have computed magnetic moment, Mulliken's population, density of states (DOS) and Compton profiles (CPs) for NiFe 2 O 4 using linear combination of atomic orbitals (LCAO) scheme with and without hybrid functional for exchange and correlation potentials. Further, theoretical CPs have been validated using isotropic CP measurement with 137Cs radio-isotope for NiFe 2 O 4. Among the considered exchange-correlation potentials within LCAO, the hybrid B3LYP scheme based momentum densities give better agreement with the experimental CP. Majority- and minority-spin DOS have confirmed the insulating nature of NiFe 2 O 4. Peculiarities of presently deduced MP data and magnetic moments are also discussed. Image 1 • Structural and magnetic response of NiFe 2 O 4 and Ni 0.95 Cr 0.05 Fe 2 O 4 using X-ray diffraction, Raman spectroscopy, FTIR spectroscopy and SQUID magnetometer. • Confirmation of impurity less single phase for both compositions by Rietveld refinement method, FTIR and Raman spectroscopy. • Computed magnetic moment, Mulliken's population, density of states (DOS) and Compton profile (CP) for NiFe 2 O 4 using LCAO with and without hybrid functional. • Validation of LCAO-B3LYP scheme for NiFe 2 O 4 using isotropic CP measurements with 137Cs radio-isotope and M-H measurements. • Analyzed spin dependent DOS and confirmation of wide band gap nature of NiFe 2 O 4 and projected use of LCAO approximations for deducing magnetic response. [ABSTRACT FROM AUTHOR]