The search for ferromagnetic materials with high Curie temperature (<i>T</i><sub>c</sub>) is a hot issue in condensed matter physics. In this work, an effective machine learning model of based on material component information established to predict variety temperature. Based the collected data 1568 materials, and taking as descriptors, work four efficient models are con...

In this paper, using high order perturbative series expansion method, the critical exponents of the order parameter and susceptibility in transition from ferromagnetic to disordered phases for 1D quantum Ising model in transverse field, with ferromagnetic nearest neighbor and anti-ferromagnetic next to nearest neighbor interactions, are calculated. It is found that for small value of the frustr...

%e have measured the ac magnetic susceptibility of the model dilute dipolar-coupled Ising system LiHo„Y& -„F4. The x 0.46 material displays an ordinary ferromagnetic transition, while the x 0.045 and 0.167 samples are two very different magnetic glasses. Thermal relaxation times are more than five times longer for x 0.167 than for x ~0.045. In addition, the more concentrated glass shows history...

Ferromagnetism is predicted in undoped diluted magnetic semiconductors illuminated by intense sub-band-gap laser radiation. The mechanism for photoinduced ferromagnetism is coherence between conduction and valence bands induced by the light which leads to an optical exchange interaction. The ferromagnetic critical temperature T(C) depends both on the properties of the material and on the freque...

We study a recovery problem for an unknown boundary data at the boundary part Γnon in static electromagnetism. We work in a bounded domain Ω ⊂ Rn with a Lipschitz continuous boundary. We consider a problem of determining the coefficient λ. This coefficient represents one of the ferromagnetic material characteristics occupying this domain. The existence and uniqueness of a weak solution is prove...

The magnetic moment reversal at each of the two inequivalent Nd sites in a single crystal of ferromagnetic Nd(2)Fe(14)B is probed by dichroic resonant diffraction of circularly polarized x rays. The results, supported by theory, show that the c-axis intrinsic magnetic stability of this superior permanent magnetic material arises predominantly at one of the Nd sites (g). The other site (f) under...

The vanadosilicate zeolite AM-6 is shown by a combination of spectroscopic techniques (UV-vis, Raman, XPS, XAS and EPR) to contain linear chains of alternating V=O and V-O bonds. The V(IV) ions in these chains are ferromagnetically coupled, and an excellent fit a to the susceptibility data with a one-dimensional Heisenberg model is obtained with J = 0.66(1) cm(-1). AM-6 is thus the first report...

We report on electrical measurements of the effective density of states in the ferromagnetic semiconductor material (Ga,Mn)As. By analyzing the conductivity correction to an enhanced electron-electron interaction the electrical diffusion constant was extracted for (Ga,Mn)As samples of different dimensionality. Using the Einstein relation allows us to deduce the effective density of states of (G...

In this paper we study a model of ferromagnetic material with hysteresis effects. The magnetic moment behaviour is described by the non-linear Landau-Lifschitz equation with an additional term modelling the hysteresis. This term takes the form of a maximal monotone operator acting on the time derivative of the magnetic moment. In our model, it is approximated via a relaxing heat equation. For t...

A GaMnAs nanoelectromechanical resonator is used to obtain the first measurement of magnetostriction in a dilute magnetic semiconductor. Resonance frequency shifts induced by field-dependent magnetoelastic stress are used to simultaneously map the magnetostriction and magnetic anisotropy constants over a wide range of temperatures. Owing to the central role of carriers in controlling ferromagne...