Dependence of magnetomechanical performance of CoGaxFe2−xO4 on temperature variation

Abstract

Electronic origin of the negligible magnetostriction of an electric steel Fe1-xSix alloy: A density-functional study J. Appl. Phys. 111, 063911 (2012) Modeling plastic deformation effect on magnetization in ferromagnetic materials J. Appl. Phys. 111, 063909 (2012) Magnetic and calorimetric studies of magnetocaloric effect in La0.7-xPrxCa0.3MnO3 J. Appl. Phys. 111, 07D726 (2012) Converse magnetoelectric effect dependence with CoFeB composition in ferromagnetic/piezoelectric composites J. Appl. Phys. 111, 07C725 (2012) A model-assisted technique for characterization of in-plane magnetic anisotropy J. Appl. Phys. 111, 07E344 (2012) Additional information on J. Appl. Phys. The temperature dependence of the magnetoelastic properties of the CoGa x Fe 2Àx O 4 system (for x ¼ 0.0, 0.2, and 0.4) has been studied. It has been shown that increase in temperature resulted in reduced magnetostrictive hysteresis. For both CoGa 0.2 Fe 1.8 O 4 and CoGa 0.4 Fe 1.6 O 4 , the measured magnetostriction amplitudes were higher at 250 K than at 150 K. It was also shown that the temperature stability of magnetostriction in CoGa 0.2 Fe 1.8 O 4 is higher than that of the other compositions studied which is important for sensor applications. The highest strain sensitivity was obtained for CoGa 0.2 Fe 1.8 O 4 at 250 K. Results demonstrate the possibility of tailoring magnetomechanical properties of the material to suit intended applications under varying temperature conditions.

Influence of Ga-concentration on the electrical and magnetic properties of magnetoelectric CoGaxFe2−xO4/BaTiO3 composite

“…This decrease is related to the weakening of the exchange coupling with substitution of non-magnetic Ga 3þ which would affect magnetostriction. A similar observation was reported in magnetostrictive properties of Ga-substituted cobalt ferrite at 300 K. 14 The observation that the magnetostriction plots do not saturate as would be obtained in only CoGa x Fe 2Àx O 4 phase indicates the coupling of the strains on the BT and CoGa x Fe 2Àx O 4 phases.…”

“…14,15 Such may also results in cobalt ions being displaced into the B-sites. Since the net magnetic moment in spinel ferrites is obtained by m ¼ P m BÀsites À P m AÀsites , substituting for Fe 3þ on the A-sites and displacing more Co 2þ into the B-sites would increase magnetic moment.…”

Temperature dependence of the structural, magnetic, and magnetostrictive properties of zinc-substituted cobalt ferrite

“…Strain derivative is often enhanced at low cation concentration but decreases at higher concentrations. 3,7,13,14 Some exceptions are Ga-substitution 12 for which strain derivative was enhanced at relatively higher Ga concentration (x ¼ 0.4 at 300 K) and Mg-substitution 24 for which strain derivative decreased with Mg substitution. In those studies, Ga and Mg were substituted for Fe.…”

“…Low concentration of Zn substituted for Co is desirable as it has been shown in previous studies that some desirable properties deteriorate when high concentrations of non-magnetic cations are substituted into cobalt ferrite. 3,12,13 EXPERIMENTAL DETAILS Sample synthesis and pelletizing Samples were prepared by auto-combustion method using Co(NO 3 ) 2 .6H 2 O, Fe(NO 3 ) 2 .9H 2 O, Zn(NO 3 ) 2 .6H 2 0, and NH 2 CH 2 COOH as precursors. The chemical precursors were thoroughly mixed in their appropriate ratios and heated to evaporate the water and to encourage auto-ignition of the mixture.…”

Magnetic sensors based on topological insulators

“…The microstructure and crystal structures are similar in CoGaxFe2-xO4/BaTiO3 (x = 0 -0.3). The electron images and XRD patterns in observation was previously reported in which it was stated that Ga 3+ has A-site preference [120,121]. Such may also results in cobalt ions being displaced into the B-sites.…”