On the magnetic compensation of magnesium doped Ni-Cr ferrites

Abstract

Mg-substituted ferrites NiMg x Fe 1 . 1 − ( 2 / 3 )x Cr 0 . 9 - O 4 ( 0 ≤ x ≤ 0 . 4 ) were studied using X-ray diffraction, Mössbauer spectroscopy, and magnetic measurements. X-ray diffraction patterns show that all samples have cubic spinel structure. The temperature-dependent magnetic measure- ments revealed that the compensation point T K of NiFe 1 . 1 - Cr 0 . 9 O 4 starts to approach the Curie temperature T C as Mg 2 + substitution of Fe 3 + increases, until the magnetic compensation disappears at composition x = 0 . 4. The mag- netization data at all concentrations are discussed in the light of Néel’s molecular field model given the cations distribu- tion obtained using the Mössbauer spectra analysis.