Contributions of magnetocrystalline and magnetoelastic energy in spinels. 1975.

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The origins and consequences of magnetocrystalline anisotropy energy (MAE) and magnetoelastic coupling in terms of the electronic structure of 4f and 5f elements are reviewed. In the heavy rare‐earth metals, the large molecular fields dominate and the MAE arises primarily from the crystalline electric field (CEF) with modifications due to the Author: Børje Johansson, Michael S.S.

Brooks. The dependence of the uniaxial magnetic anisotropy energy on the Co thickness in these superlattices showed significant systematic differences for each of the three crystal orientations. These variations result entirely from differences in the volume contribution to the anisotropy. Estimates of the magnetocrystalline and magnetoelastic Cited by: To obtain symmetric Co/Cu interfaces the Co layers were covered with a 12 Å Cu layer.

Finally, a 25‐Å‐thick Au protective layer was deposited. Low‐energy electron‐diffraction studies were used to obtain the structural data of the films.

All relevant anisotropy contributions—the magnetocrystalline anisotropy, and the uniaxial in‐plane and out‐of‐plane anisotropy contributions Cited by:   1. Introduction. Nanoporous anodic aluminum oxide (AAO) membranes have attracted significant attention in recent years, as excellent templates for the low-cost fabrication of ordered arrays of nanowires (NWs) and nanotubes.The combination of these templates with simple filling methods allows one to easily tune the final geometrical parameters of the grown nanostructures, such as Cited by: 2.

Three regimes of film growth and associated anistropy behavior are identified: cohernet growth, in-plane anisotropic and isotropic strain relaxation. The magnetocrystalline bulk anisotropy contribution with easy axes along the in-plane 〈〉 direction is found to be largely suppressed for film thicknesses smaller than (50 ± 10) by:   The magnetocrystalline and shape anisotropies pull the magnetization to the MnAs plane, increasing the field necessary to saturate magnetization along such direction, but the magnetoelastic anisotropy (the influence of biaxial strain is accounted by the term 1 (B 1 + 2B 3)) opposes or favors them, increasing or lowering the field necessary to.

The origins and consequences of magnetocrystalline anisotropy energy (MAE) and magnetoelastic coupling in terms of the electronic structure of 4f and 5f elements are reviewed. B 1 and B 2 are called magnetoelastic coupling constants, and m i (i = x,y,z) are, as before, the magnetization direction cosines referred to the edges of the cubic crystal to the presence of an energy contribution of the form of Eq.

Details Contributions of magnetocrystalline and magnetoelastic energy in spinels. 1975. EPUB

(), a crystal of given magnetization naturally tends to deform in a way that decreases its total free energy. journal of - 0 WE magnetism -- M and magnetic - O materials ELSEVIER Journal of Magnetism and Magnetic Materials () Magnetocrystalline and magnetoelastic anisotropies in () bcc thin films and superlattices E.

du Tremolet de Lacheisserie *, O.F.K. Mc Grath Laboratoire de Magnetisme Louis Neel, CNRS-UJF, B.P. Grenoble cedex 9, France. We report on an unexpected suppression of the magnetocrystalline anisotropy contribution in epitaxial fcc Co() films on Cu() below a thickness of dc=(50+/) Å.

A current modern status of magnetostriction (MS), magnetoelastic (MEL) coupling and magnetoelasticity (ME) theory and models (spin waves, band MS Hubbard forced MS, spin fluctuations, weak ferromagnets, ab initio, MEL parameters calculation, strongly correlated systems) is presented, particularly the standard theory for magnetostriction (i.e., built up of MEL Hamiltonians and.

Magnetic spinels including ferrites are insulating magnetic oxides and chalcogenides with strong coupling to microwave frequencies and low eddy current losses making them indispensable for applications in wireless communications.

The 13 chapters and preface of this book discuss other potential applications of magnetic spinels along with various methods used for their synthesis and.

The magnetoelastic contribution to the in-plane anisotropy results as (B 2 −B 1)(11 − 33) = − MJ m −3. This value compares reasonably well with the value of − MJ m −3, calculated for 13 layers of Fe from the anisotropy study of Elmers and Gradmann. We conclude that the strain-dependent magnetoelastic anisotropy is.

It should be taken into account that the magnetoelastic anisotropy energy is a field-dependent contribution to the free energy of the system, unlike the case of the magnetocrystalline anisotropy contribution and, therefore, the sum of both terms can be different at different applied magnetic fields in Ho in a much greater extent than in Tb or Dy.

Magnetostatic energy Up: Thermodynamic relations Previous: Exchange energy Contents Magnetocrystalline anisotropy energy.

The Heisenberg Hamiltonian is completely isotropic, and its energy levels do not depend on the direction in. The magnetocrystalline and magnetoelastic anisotropy energies of bcc () thin films and superlattices are predicted from group theory and calculated within the. The magnetocrystalline anisotropy constants K u1 and K u2 of Co–Ni alloys containing Ni up to 30% were measured at temperatures between 77 K and K by means of a torque magnetometer.

For the alloys containing Ni less than about 7%, the sign of K u1 was found to change from positive to negative in the h.c.p. phase. The temperature at which K u1 becomes zero was found to increase from K.

where is the stress and is the angle between the magnetisation and stress directions. For positive, as in metallic iron, the easy magnetic direction will be along a direction of tensile stress, or perpendicular to a compressive stress.

Strain in thin films and multilayers can be produced by the growth conditions, such as lattice mismatch between layers or thermal stress caused by differences.

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THE PHONON-INDUCED TEMPERATURE DEPENDENCES OF MAGNETOCRYSTALLINE ANISOTROPY CONSTANTS C. BATES Physics Department, The University, Nottingham, England and H. SZYMCZAK Institute of Physics, Polish Academy of Sciences, Warsaw, Poland The phonon-induced contribution to magnetocrystalline anisotropy constants.

In iron this is the (0,0,1) direction, whereas in nickel it is the (1,1,1) direction. The free energy of the crystal thus contains a term which couples the magnetisation direction to the crystal lattice.

Description Contributions of magnetocrystalline and magnetoelastic energy in spinels. 1975. FB2

This is known as the magnetocrystalline anisotropy energy [1]. γ σ scales the magnetoelastic energy term. Hence, if it is observed that the theory fits the experiment well at low stress but the field required to saturate the material at higher stresses are over predicted, the contribution of magnetoelastic energy are reduced by scaling it with γ σ.

However, γ σ does not affect the smoothness of the. Thermodynamic theory. The magnetocrystalline anisotropy energy is generally represented as an expansion in powers of the direction cosines of the magnetization. The magnetization vector can be written M = M s (α,β,γ), where M s is the saturation e of time reversal symmetry, only even powers of the cosines are allowed.

The nonzero terms in the expansion depend on the. Magnetostriction and magnetoelastic coupling Magnetostriction (from Wikipedia) Magnetostriction is a property of ferromagnetic materials that causes them to change their shape when subjected to a magnetic field. The effect was first identified in by James Joule when observing a sample of nickel.

Standard magnetostriction theory constructs a free energy from three terms: the energy of a rigid magnetized body, the energy of a nonmagnetic elastic body, and the volume integral of an interaction energy‐density linear in the strains.

This procedure is open to three criticisms. First, strains invalidate the magnetic calculation; in particular, the magnetostatic self‐energy is strain.

[Show full abstract] magnetocrystalline anisotropy, the magnetoelastic coupling and the extraordinary contributions to the magnetotransport. Furthermore, the combination of large magnetic. In this chapter, the nature of magnetic ordering in cobalt‐based spinels Co3O4, Co2SnO4, Co2TiO4, and Co2MnO4 is reviewed, and some new results that have not been reported before are presented.

A systematic comparative analysis of various results available in the literature is presented with a focus on how occupation of the different cations on the A‐ and B‐sites and their. The magnetocrystalline anisotropy energy, which arises mainly from the spin-orbit coupling correction to the Hamil-tonian, is a very small correction to the magnetic energy.

There have been many measurements on magnetic anisot-ropy constants for both the high- and low-temperature phases of magnetite–34 Recent experiments on the anisotropy of.

Next: Zeeman energy Up: Thermodynamic relations Previous: Magnetocrystalline anisotropy energy Contents Magnetostatic energy. The origin of domains still cannot be explained by the two energy terms above.

Another contribution comes from the magnetostatic self-energy, which originates from the classical interactions between.

Keywords: magnetostriction, magnetoelastic losses, magnetoelastic de Haas van Alphen oscillations. 1 INTRODUCTION. The magnetostriction is an important intrinsic property of all kinds of magnetically ordered materials.

This property is interesting for sensor or actuator applications. On the other side it determines the magnetoelastic energy. The previously reported mechanism of exchange isolation that was proposed to explain the absence of strong positive magnetocrystalline anisotropy effects from Co 2 + ions in LiTi spinel ferrite is approximated by a three‐cation superexchange model.

This simplified system is then analyzed in terms of the dependence of the single‐ion Co 2 + anisotropy contribution on magnetic dilution. The net anisotropy includes magnetocrystalline, magnetoelastic, and shape terms.

The magnetocrystalline anisotropy term K 1 for iron garnets is typically negative favoring a easy axis. A prior study of Ce:YIG films gave K 1 = − kJ m −3. 11 A. The coercivity μ 0 H c = T at K was much larger than that expected from magnetocrystalline anisotropy.

The smallest effective anisotropy constant is suggested to be MJ m −3 when the coercivity mechanism is controlled by coherent rotation .The influence of the substrate Gd2(MoO4)3 ferroic phase transition on the magnetization of ferromagnetic nickel thin film was investigated using vibrating sample magnetometer.