We investigated the magnetic and ferroelectric properties of c-axis oriented orthorhombic phase HoMnO(3) (o-HMO in Pbnm symmetry setting) thin films grown on Nb-doped SrTiO(3)(001) substrates. The o-HMO films exhibit an antiferromagnetic ordering near 42 K, irrespective of the orientation of the applied field. However, an additional magnetic ordering occurring around 35 K was observed when the field was applied along the c-axis of o-HMO, which was absent when the field was applied in the ab-plane. The magnetocapacitance measured along the c-axis showed that although there is evidence of dielectric constant enhancement when the temperature is below 35 K the expected abrupt change in dielectric constant appears at a much lower temperature and reaches maximum around 13.5 K, indicating that the low-temperature c-axis polarization might be related to the ordering of the Ho(3+) moment. The lattice constant analyses using x-ray diffraction and the observation of a slight magnetization hysteresis suggest that the weak second magnetic transition along the c-axis at 35 K might be more relevant to the strain-induced effect on antiferromagnetism.

Effect of dopants on the soft magnetic properties and high frequency characteristics of FeCoBM thin films (M = Ti, Nb, Hf, and Ta) have been studied. For (Fe0.55Co0.45)(100-x)B(x) (x = 5-15) thin films, with the increase of B content, the resistivity was increased because B could decrease the crystallinity of the films. The (Fe0.55Co0.45)90B10 thin film showed the optimum properties, where 4piM(s) = 16.1 kG, H(ce) = 64.2 Oe, H(ch) = 13.5 Oe, H(k) = 310 Oe and p = 338 microomega-cm. To reduce the coercivity of the film, the elements M, including Ti, Nb, Hf, and Ta, were selected to substitute for B in the FeCoB films. It was found that (Fe0.55Co0.45)90B6Ti2Nb2 thin film after annealing at a temperature of 200 degrees C for 30 min showed the optimal properties, where 4piM(s) = 15.8 kG, H(ce) = 4.8 Oe, H(ch) = 3.6 Oe, H(k) = 224 Oe and p = 290 microomega-cm. The theoretically calculated ferromagnetic resonance frequency of the developed films can be higher than 5 GHz.

Physicists and engineers often encounter problems involving the stresses and strains in a body with a combination of elastic, creep and thermal, and plastic strains. Methods of analyzing elastic bodies subject to surface and body forces are more familiar to analysts than the corresponding analysis of inelastic bodies. It is the aim of the present note to show the analogy between the inelastic strain, which consists of a combination of thermal, creep, and plastic strains, and applied forces. This analogy is well known for thermal stresses. It is generalized here to include creep and plastic strain in both cubic crystals and isotropic media. Let rij and efj be the stress and strain components referred to a set of rectangular coordinates. The strain consists of the elastic strain et' and the inelastic strain ell' which is composed of thermal strain etj>, creep strain eij, and plastic strain ejj, so that e j = esj' + ej', (1) eljl = edij + eijj + eij, (2) Recently, T. Y. Thomas' has given a general compact form of the elastic stressstrain relationship in cubic crystals. This relationship has made possible the following simple formulation of the above-mentioned analogy for cubic crystals. Let a denote a crystal axis of the cubic crystal. Thomas has shown