This article presents a phenomenological dynamic phase transition theory for ferromagnetism, leading to a precise description of the dynamic transitions, and to a physical predication on the spontaneous magnetization. The analysis also suggests asymmetry of fluctuations in both the ferromagnetism and the PVT systems.

We present a quantitative theory for the effects of correlated doping on the ferromagnetism of diluted magnetic semiconductors. It predicts that room temperature ferromagnetism should be possible in homogeneous, but correlated, samples of MnxGa1−xAs. The theory predicts lower critical temperatures for MnxGa1−xN. Typeset using REVTEX email:[email protected] Also in the CNRS,email:[email protected] emai...

We propose a model of carrier-mediated ferromagnetism in semiconductors that accounts for the temperature dependence of the carriers. The model permits analysis of the thermodynamic stability of competing magnetic states, opening the door to the construction of magnetic phase diagrams. As an example, we analyze the stability of a possible reentrant ferromagnetic semiconductor, in which increasi...

Ultrathin metal-free g-C3N4 nanosheets with intrinsic room temperature ferromagnetism were synthesized by heating urea in an airtight container at different temperatures. Results indicate that the samples' saturation magnetization increases with the carbon defect concentration, revealing its carbon defect related ferromagnetism. Moreover, we further confirmed the defect induced ferromagnetic na...

Single phase and strained LuMnO(3) thin films are discovered to display coexisting ferromagnetic and antiferromagnetic orders. A large moment ferromagnetism (≈1μ(B)), which is absent in bulk samples, is shown to display a magnetic moment distribution that is peaked at the highly strained substrate-film interface. We further show that the strain-induced ferromagnetism and the antiferromagnetic o...

We prove basic theorems about the ground states of the S=1 Bose-Hubbard model. The results are quite universal and depend only on the coefficient U2 of the spin-dependent interaction. We show that the ground state exhibits saturated ferromagnetism if U2<0, is spin-singlet if U2>0, and exhibits "SU(3)-ferromagnetism" if U2=0, and completely determine the degeneracy in each region.

We show that relic fermions of the Big Bang can enter a ferromagnetic state if they possess a magnetic moment and satisfy the requirements of Stoner theory of itinerant ferromagnetism. The domain walls of this ferromagnetism can successfully simulate Dark Energy over the observable epoch spanning ∼ 10 billion years. We obtain conditions on the anomalous magnetic moment of such fermions and thei...

We report the use of targeted p- and n-type chemical perturbations to manipulate high-T(C) ferromagnetism in Mn(2+):ZnO and Co(2+):ZnO in predictable and reproducible ways. We demonstrate a clear correlation between nitrogen and high-T(C) ferromagnetism for Mn(2+):ZnO and an inverse correlation for Co(2+):ZnO, both as predicted by recent theoretical models. These chemical perturbations reveal r...

The Guglielmi detachable coil, a platinum microcoil used in the endovascular treatment of intracranial aneurysms, was studied in vitro for its MR imaging artifacts, heat production, and ferromagnetism. In addition, imaging artifacts were studied in vivo in eight patients who had undergone therapeutic placement of these coils. These devices displayed a very low level of MR artifact and no ferrom...

We address the possible occurrence of ultracold atom ferromagnetism by evaluating the free energy of a spin polarized Fermi gas to second order in its interaction parameter. We find that Hartree-Fock theory underestimates the tendency toward ferromagnetism, predict that the ferromagnetic transition is first order at low temperatures, and point out that the spin coherence time of gases prepared ...