We study a two-leg antiferromagnetic spin-1/2 ladder in the presence of a staggered magnetic field. We consider two parameter regimes: strong ͑weak͒ coupling along the legs and weak ͑strong͒ coupling along the rungs. In both cases, the staggered field drives the Haldane spin-liquid phase of the ladder towards a Gaussian quantum criticality. In a generalized spin ladder with a non-Haldane, spontaneously dimerized phase, the staggered magnetic field induces an Ising quantum critical regime. In the vicinity of the critical lines, we derive low-energy effective field theories and use these descriptions to determine the dynamical response functions, the staggered spin susceptibility, and the string order parameter.

On the basis of the co-effect of the crystal field with a random distribution and the molecular field and using anisotropic static magnetic couplings, we calculated the polar angle Θ of the magnetic moment in 15×(26 Å Tb/40 Å Fe)+40 Å Fe multilayers as function of temperature from 4.2 to 300 K, which agrees well with experiment. As a result of the calculation, the width of interface mixing layer and the coefficient of the crystal field are determined.

This article reports the effect of Al doping into MnBiSi films on the structure and magneto-optical properties of the parent. Under suitable Al doping, the x-ray diffraction peaks of (002) and (004) move to a larger 2Θ value related to that of MnBiSi. Moreover, two satellite peaks appear beside the main (002) and (004) peaks of MnBiAlSi. Such structural distortion due to Al doping results in an increased Kerr rotation angle, an effective perpendicular anisotropy constant Ku, as well as improvement of the thermal stability of MnBiSi.

Using electrolytic polishing, the coercive field, Hc, and the magnetic anisotropy, Keff, as a function of the thicknéss is invèstigated. After removing of top and wheel‐side, the surface coercive field decreases. It is shown that the anomaly of the surface coercive field originates from the surface Soyghness and from internal stresses which are induced during the quenching process. For stronger thinning treatments Hc, is found to increase. In magnetostrictive amorphous alloys as Fe40Ni40B20 internal stresses are the source of the magnetic anisotropy, Keff. The surface roughness is found not to induce the surface anomaly of Keff.