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This paper presents an exact analysis of deformation and stress field in a finite cylinder under axisymmetric boundary conditions. The problem is formulated based on the state space formulation for transversely isotropic piezoelectric media. Upon the separation of variables method, we get a set of general solutions spanning over the complete solution space to cover all axisymmetric boundary conditions. Furthermore, a rigorous solution which satisfies the end conditions is determined by using eigenfunction expansion. Numerical results show that the local effect is significant but confined to boundary layer near the fixed end where the displacement and stress are remarkably different from those of other regions.

A novel eigenvector expansion method under the symplectic system is introduced for boundary condition problems of thermo-viscoelastic materials. On the basis of the state space formalism and the use of the Laplace integral transform, the general solutions of the governing equations, zero and non-zero-eigenvalue eigenvectors, are obtained analytically. Since the eigenvectors are expressed in concise analytical forms, the adjoint symplectic relation in the Laplace domain is generalized to the time domain. Using this method, various boundary conditions and the particular solution of non-homogeneous governing equations can be conveniently described by combinations of the eigenvectors.

In this paper, barium hexaferrite thick films with thickness of 80 microns were prepared on alumina substrates by screen printing method for applications in self-biased planar microwave devices. The influences of sintering temperature on the microstructures and magnetic properties of barium ferrite (BaM) thick films were investigated. The results show that with the increase of sintering temperature, the grain size increases and the porosity of the BaM thick films decreases. When the sintering temperature is below 1200 °C, the BaM thick films show magnetic properties with coercive force of about 3.5 kOe and magnetization at 20 KOe (4πM20kOe) of about 1750 Gs. When the sintering temperature is greater than 1200 °C, the magnetic properties deteriorate remarkably and exhibit a coercive force of 0.4 kOe and 4πM20kOe of about 480 Gs due to the over-sintering and diffusion of Al atoms into the BaM thick films. A new non-ferromagnetic phase Al13Ba7 is formed, which is detected by XRD.

The driving field of the magnetostrictive thin film actuator should be as small as possible in order to develop miniature devices. The aim of this paper is to reduce the driving field by varying the structural and the material parameters of the substrate of the cantilever in the actuator based on the finite element calculation. The influences of the geometric and the material parameters on the reference driving field have been studied. The results show that the reference driving field is sensitive to the length of the cantilever, the thickness of both the magnetostrictive film and the substrate, and also the Young's modulus of the substrate. The length of the cantilever should be long enough. In order to achieve a small driving field, the thickness of both the magnetostrictive film and the substrate should be carefully designed according to the ratio of the Young's modulus of the substrate to that of the film.

In this paper, the influences of depositing angles on TbFe film magnetic and magnetostrictive characteristics were discussed. TbFe films were deposited by DC magnetron sputtering. With the decrease of depositing angles from 900 to 150, TbFe film in-plane magnetization measured at 1600kA.m-1 external field is greatly increased. With the decrease of depositing angles from 900 to 150, the magnetostrictive saturation field is decreased. TbFe film in-plane magnetostriction is improved when depositing angles are changed from 900 to 150. Magnetic domain structures detected by MFM indicates that film easy magnetization direction is gradually changed from perpendicular to parallel with the decrease of depositing angles. The variation of film magnetic and magnetostrictive performances can be explained by the oblique anisotropy associated with columnar grain morphology of the films.

In this paper, the influences of annealing temperature on TbFe magnetostrictive film magnetic and magnetostrictive characteristics were discussed. TbFe films were prepared by RF magnetron sputtering. XRD patterns indicate that polycrystalline films consisting mainly of a-Fe and TbFe2 Laves phase could be obtained through rapid cycle annealing process (RCAP) at higher annealing temperature. Grain sizes could be controlled through varying annealing temperature. From film hysteresis loops measured by VSM, it has been found that the annealing treatment can improve TbFe film in-plane magnetization at 1600 kA.m-1 external field, and decrease in-plane coercivity. Magnetostriction of annealed TbFe films measured by optical cantilever deflectometer is better than as-deposited films at 40 kA.m-1 external magnetic field.