Nonmagnetic Indium Research Articles

DFT Study of Effect of Hydrostatic Pressure on Structural, Electronic and Magnetic Properties of In0.875Cr0.125P

In this paper, the effect of hydrostatic pressure on structural, electronic and magnetic properties of In0.875Cr0.125P Diluted Magnetic Semiconductor (DMS) in Zinc Blende (B3) phase has been studied at 0 GPa to 26 GPa. The calculations have been performed using Density Functional Theory as implemented in the Spanish Initiative for Electronic Simulations with Thousands of Atoms code (SIESTA) using LDA+U (U=3) as exchange-correlation (XC) potential. The study of electronic structures and magnetic properties show that In0.875Cr0.125P is half metallic in nature and this behaviour is maintained at given pressure range. It is found that forbidden energy band gap increases with increase in pressure due to shifting of valence band maximum and conduction band minimum of energy levels. The investigation of structural properties shows that lattice constant and volume of compound decreases along with increase in total energy of compound with applied pressure. The study of induced local magnetic moment values show their continuous increase on non-magnetic indium and phosphorus atoms with increasing pressure.

Magnetic interactions and spin-wave stiffness constant of In-substituted yttrium iron garnets

Abstract Indium-substituted yttrium iron garnet samples, Y3Fe5−xInxO12 (x = 0–0.7, step 0.1), were prepared using a citrate solgel method. Synchrotron X-ray diffraction (SXRD) measurements combined with the Rietveld refinement technique were used to investigate the crystallization, structure parameters and lattice distortion in the samples. Magnetization and Curie temperature of the samples were measured with the SQUID and VSM equipments. The non-magnetic indium ions were found to reside at the octahedral sites, leading to an increase of the total magnetization and a decrease in the Curie temperature. Molecular field coefficients Naa, Ndd and Nad were determined by fitting the experimental thermomagnetization curves in the framework of a two-sublattice ferrimagnetic model. The stiffness constant of the spin waves, D, in these samples was calculated based on the exchange interaction constants, Jij, and its temperature dependence was derived for the sublattice magetizations. The calculated results for D(T) are in good agreement with the experimentally measured data and are significantly large around room temperature.

Study of effect of hydrostatic pressure on structural, electronic and magnetic properties of In0.75Mn0.25P using density functional theory

In this paper, the investigation of effect of hydrostatic pressure on the structural, electronic and magnetic properties of In0.75Mn0.25P Diluted Magnetic Semiconductor in Zinc Blende (B3) phase at 0 GPa–26 GPa pressure range is done using first principal calculations as implemented in Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code.The theoretical investigation of electronic and magnetic properties of this compound represents that the compound is half-metallic ferromagnet and show 100% spin polarization at different values of pressure. It is found that forbidden energy band gap increases with increase in pressure as spin polarized band structures experience changes with applied pressure. The calculated results show that lattice constant and volume of compound decreases along-with increase in induced local magnetic moments values of non-magnetic indium and phosphorus atoms with applied pressure.

Effects of In3+ site occupancy on the magnetic properties of M-type strontium hexaferrites

Effects of nonmagnetic indium ion substitution on magnetic properties of M-type strontium hexaferrites SrFe12-xInxO19 (x=0, 0.25, 0.5, 0.75, and 1) have been studied by crystallographic and magnetic measurements. Samples were prepared by citric auto-combustion method. Rietveld analysis of X-ray diffraction profiles showed that the samples were single phase with the space group P63/mmc and lattice constants a and c increased linearly with In3+ content. Mössbauer spectra showed that In3+ mainly replaced Fe3+ ions in 4f2 sites and that 12k subspectra split into two distinct components 12k1 and 12k2. Analysis of hysteresis curves showed that while the coercive force and the magnetic anisotropy constant decreased thru the whole doping range x, the saturation magnetization first increased until x=0.5 and decreased thereafter. This behavior was explained by the existence of two competing interactions in terms of nonmagnetic indium substitution.

Structural and magnetic properties of single-crystalline spinel systems ZnCr 2− x In xSe 4

The single crystals of In 3+-doped zinc chromium selenide spinel ZnCr 2Se 4 were prepared by a chemical transport method and characterized by X-ray diffraction, magnetic measurements and ESR spectroscopy in order to examine an effect of nonmagnetic indium on the structural and magnetic properties of the system. The X-ray diffraction analysis has shown that only small amount of In entered the octahedral sites in the cubic spinel structure with space group F d 3 ¯ m . As compared with parent ZnCr 2Se 4, the unit cell dimensions increased slightly with increasing In content, however at the In concentration of about 10%, the structures exhibited a certain amount of octahedral vacancies. For examined compounds the Neel temperature is very similar to that of the parent spinel ZnCr 2Se 4, whereas the paramagnetic Curie temperature is much lower (of about 59 K) than that for matrix. It means that the frustration introduced into systems by B-sublattice indium dilution reflects the change of ferromagnetic interactions in the magnetic exchange. The temperature dependence of the ESR linewidth over region ( T/ T N)>8 is interpreted by an occurrence of spin–phonon interaction. The interesting feature of the low-field magnetization is that the magnetic irreversibility observed in the separation of the FC and ZFC curves below T N is consistent with a new, weak resonance-like features.

Magnetic properties of spinel oxides, InFe MO 4 ( M=Mg, Co and Ni)

The impact of cation composition on the magnetic properties in the InFe MO 4 mixed spinel system ( M=Mg,Co,Ni) has been studied by means of AC/DC magnetization and 57Fe Mössbauer spectroscopy measurements. Existence of a glassy state was confirmed for InFeCoO 4 by AC magnetization measurement, whereas the shape of the hysteresis loop in M – H measurement suggests the presence of strong interactions between the magnetic clusters. Soft magnet-type behaviour was observed for InFeNiO 4 with the value of saturation magnetization suggesting the presence of canted spin structure as a consequence of the presence of nonmagnetic indium. In the case of InFeMgO 4 the further magnetic dilution due to nonmagnetic magnesium was observed to lead to clear decay in long-range magnetic order, although the presence of short-range magnetic order was confirmed by M – H and 57Fe Mössbauer measurements.

Enhanced room-temperature geometric magnetoresistance in a modified van der Pauw disk

We propose a modified design based on the van der Pauw disk to generate a very large geometric magnetoresistance owing to Hall effect. the conventional disk is a van der Pauw disk (vdP), in which a concentric circular gold plate is embedded in homogeneous nonmagnetic indium antimonide [Solin et al., Science 289 (2000) 1530.]. Because of special structures and InSb's high mobility, it exhibits strong Hall effect and shows a magnetoresistance of 100% under a magnetic field of 500 Oe at room temperature. In the modified design, half of the gold plate is instead of an ellipse-shape. Higher magnetoresistance in this new design than that of vdP is predicted under low mganetic field at room temperature.

A New van Pauw Disk to Enhance Geometric Magnetoresistance at Room Temperature

A modified design based on the van der Pauw disk to generate a very large geometric magnetoresistance owing to Hall effect is proposed. The conventional disk is a van der pauw disk ( vdp ), in which a concentric circular gold plate is embedded in homogeneous nonmagnetic indium antimonide (S. A. Solin et al., Science 289, 1530 (2000)). Because of the special structures and high mobility of InSb, the vdp -disk exhibits strong Hall effect and shows a magnetoresistance of 100% under a magnetic field of 500 Oe at room temperature. In our modified design, half of the gold circle is replaced with half of a gold ellipse. Higher magnetoresistance in this new design is predicted at room temperature.

A New van Pauw Disk to Enhance Geometric Magnetoresistance at Room Temperature

A modified design based on the van der Pauw disk to generate a very large geometric magnetoresistance owing to Hall effect is proposed. The conventional disk is a van der pauw disk ( vdp ), in which a concentric circular gold plate is embedded in homogeneous nonmagnetic indium antimonide (S. A. Solin et al., Science 289, 1530 (2000)). Because of the special structures and high mobility of InSb, the vdp -disk exhibits strong Hall effect and shows a magnetoresistance of 100% under a magnetic field of 500 Oe at room temperature. In our modified design, half of the gold circle is replaced with half of a gold ellipse. Higher magnetoresistance in this new design is predicted at room temperature.

Enhanced Room-Temperature Geometric Magnetoresistance in Inhomogeneous Narrow-Gap Semiconductors

A symmetric van der Pauw disk of homogeneous nonmagnetic indium antimonide with an embedded concentric gold inhomogeneity is found to exhibit room-temperature geometric magnetoresistance as high as 100, 9100, and 750,000 percent at magnetic fields of 0.05, 0.25, and 4.0 teslas, respectively. For inhomogeneities of sufficiently large diameter relative to that of the surrounding disk, the resistance is field-independent up to an onset field above which it increases rapidly. These results can be understood in terms of the field-dependent deflection of current around the inhomogeneity.

THE GROWTH AND MAGNETIC PROPERTIES OF SINGLE CRYSTAL In-SUBSTITUTED BiCaVFe-FERRIMAGNETIC GARNET

Single crystals of the ferrimagnetie garnet Bi3-2xCa2xFe5-x-yInyVxO12 are grown by the flux method, with x = 1.35 ±0.02, y = 0-0.388. Single crystals having a dimension greater then 10mm and few inclusions can be obtained for all materials with different. In content by the technology described in this paper. The Curie temperature of all these materials is 10-30℃ higher then that of Ga-YIG with the same magnetization. The magnetic anisotropie constant drops rapidly with increase in number of the nonmagnetic indium ions. The anisotropie field falls slightly at first and then increases gradually with decrease from 530 to 200 Gauss of the saturation magnetization. The ferromagnetic resonance linewidth for the X band region increases with decreasing magnetization. It seems that there exists a relaxation mechanism which is connected with the dipole-n'arrowed model. The linewidth is about 1 to 4 Oe for the materials with the above magnetization. The best materials obtained possess an anisotropie field of 16 Oe and a linewidth of 0.7 Oe. The above results show that these materials can be employed in low frequency microwave devices.