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The martensitic transformation, crystalline structure, microstructure and shape memory effect of the Ni53.25Mn21.75Ga25 (at.%) alloy are investigated by means of Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Transmission Electron Microscope (TEM) and the standard metal strain gauge technique. The XRD results showed that the Ni53.25Mn21.75Ga25 alloy is composed of cubic parent phase at room temperature. TEM observation proved that the typical twin martensite is tetragonal structure and tweed-like contrast which is typical image for the parent phase. A large reversible transformation strain, about 0.54%, is obtained in this undeformed polycrystalline alloy due to martensitic transformation and its reverse transformation. This transformation strain is also increased to 0.65% by the external magnetic field. It is believed that the effect of the magnetic field on the preferential orientation of martensitic variants increases the transformation strain.

The magnetic and magnetoimpedance behavior of FeCuCrVSiB and ( F / SiO 2)3/ Ag /( SiO 2/ F )3( F = FeCuCrVSiB ) soft magnetic amorphous films deposited in a magnetic field have been investigated systematically. The samples were deposited by the RF sputtering with or without a static magnetic field of 900 Oe applied in the film plane. It is found that the magnetic field applied during the deposition process improves the soft magnetic properties of the sample significantly. The coercive force of the sample is about 0.8 Oe, which is much smaller than that deposited without a field. Moreover, remarkable GMI effects were obtained at relatively low frequencies, which contrasts with the samples deposited without field. In the magnetic field-deposited state, the maximum GMI ratios of 21.5% and 19.5% were achieved for the single-layer films in longitudinal and transverse fields at a frequency of 13 MHz, while for the multilayered films, the maximum values of longitudinal and transverse GMI ratios are 45% and 44% at a frequency of 6.81 MHz, respectively. These superior GMI behaviors of the as-deposited films are related to the magnetic field used in the preparation process and the inserted SiO 2 layers.

The soft magnetic properties and giant magnetoimpedance (GMI) effect of the multilayered structure (F/SiO2)3/Ag/(SiO2/F)3 (F≡Fe71.5Cu1Cr2.5V4Si12B9) films, which were prepared by radio frequency sputtering without and with a longitudinal magnetic field of about 72 kA/m, are studied. The results show that the GMI effect almost cannot be detected in the samples deposited without field, whereas, a longitudinal magnetic field applied during deposition process obviously optimizes the soft magnetic properties of the films, and noticeable GMI effect is obtained. The maximum values of the longitudinal and transverse GMI ratios are 45% and 44% at the frequency of 6.81 MHz, respectively. In addition, the dependence of magnetoimpedance ratio, magnetoresistance ratio, magnetoreactance ratio and effective permeability ratio on the frequency has been investigated. We found that the GMI spectrum curves in the longitudinal and transverse cases almost overlap for the field-deposited sample. The GMI effect is mainly a giant magnetoinductive effect at low frequencies. When f >9 MHz, magnetoreactance ratio changes to a negative, i.e., the property of reactance changes from inductive to capacitive.

The short-time dynamic behaviour of the two-dimensional classical Coulomb gas of half-integer charges on a square lattice is investigated using Monte Carlo simulations. We estimate the second-order phase transition temperature T c and all the dynamic and static critical exponents z, β and ν. The value ν = 0.77(2) obtained is different from ν = 1 in the pure two-dimensional Ising model, which provides evidence of a non-Ising exponent in the charge lattice melting transition. In addition, the dynamic critical exponent z is found to be 2.01(3), which is also different from the z = 2.165(10) accepted generally in the pure two-dimensional Ising model.

Using a GHZ-class state as a quantum channel, we investigate the remote preparation of a qubit state and that of an entangled state in noisy environments. By analytically solving the master equation in Lindblad form, we first obtain the time evolution of the GHZ-class quantum channel. Then the influence of the noises on the process of remote state preparation is considered through analytical derivation of the fidelity and numerical calculations of the corresponding average fidelity. Our results show that the fidelity depends on the noise type, the state to be remotely prepared, the GHZ-class state and the decoherence rate. Moreover, it is found that no matter whether the qubit state or the entangled state is to be remotely prepared, the maximally entangled quantum channel has a relatively stronger ability to resist the influence of noises. Besides, the effect of the bit?phase flip noise on the average fidelity is relatively stronger than that of the bit flip noise or phase flip noise.