Structure and Magnetic Properties of Li–Cu Ferrite

Abstract

X-ray diffraction was used to study the formation and structure of mixed ferrite Li 0X5À0X5x Cu x ± Fe 2X5À0X5x O 4 (where x 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0). The X-ray diffraction pattern proved that the prepared samples were formed in the spinel structure. The samples with x 0X7 have cubic structure while the samples with x 0X9, 1 have tetragonal structure. The experimental and theoretical lattice parameters a exp and a th ) were calculated for each composition. A comparison study between experimental and theoretical values was performed. The initial permeability m i was measured as a function of temperature for the above-investigated ferrite. Utilizing the initial permeability data, the Curie temperature T C was determined. T C was found to decrease with increasing Cu 2 ion content. The anomaly seen in the temperature dependence of m i was attributed to the existence of two structural phases (cubic and tetragonal phase). The magnetization M was measured at room temperature in the range of magnetizing field from 0 to 1307 Am À1 . The calculated relative permeability showed a dependence on the magnetizing field and composition. In addition, the B H loop was measured at room temperature and at constant magnetizing field H 350 Am À1 . The coercive force H c , remanence induction B r and the apparent loss energy P s were estimated. It has been found that both B r and P s are composition dependent while H c is independent of composition.

Structural phase transformation and hysteresis behavior of Cu-Zn ferrites

“…This kind of phase transformation from a tetragonal to a cubic structure was previously observed by many researchers for different ferrite systems [36]. It has been mentioned earlier that though tetragonal deformation is not perceptible from X-ray diffraction patterns, it exists due to the Jahn-Teller deformation of Cu 2+ ions, which has been identified from temperature dependence of initial permeability curves by Mazen et al [37,38]. The samples with x = 0.4 to 0.6 have a pure cubic structure, and the curves of μ' do not show any phase transformation; so, μ' increases continuously up to T C .…”

Magnetic Properties of Cu<sub>1-x</sub>Zn<sub>x</sub>Fe<sub>2 </sub>O<sub>4</sub>Ferrites with the Variation of Zinc Concen-tration

“…Thus the decrease of H c and increase of μ′ for Zn content indicates that k 1 is dominant factor. Similar decrease of H c was observed by Noorhana Yahya et al in Mg-Zn ferrites [27] and by S. A. Mazen in Li-Cu ferrites [28]. …”

Structural and Elastic Properties of Li-Ni Ferrite

“…where V A is mean atomic volume given by (M/d x )/q, M the molecular weight, q is the number of atoms in the formula unit (i.e., 7), and N A is Avogadro's number. …”

“…There are many researches that have been reported in the literature on the studies of Li-Zn, Li-Mg, Li-Ti, Li-Cd, Li-Cu, and Li-Ga ferrites [3][4][5][6][7][8]. However, little information is available in the literature regarding the Li-Ni ferrite.…”