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In the present work, the diffusion mechanism of gas atom (C, N) into Sm2Fe17 lattice has been investigated. Results indicate that gas atoms (C, N) under different states of gas absorption content x in Sm(2)Fe(17)Z(x) (Z=C, N) are of different diffusive activity due to the interaction strength between gas atom and interstitial site of Sm2Fe17 molecule. In the region of x x(0), such interaction is small and part of nitrogen atom with amount of Delta x=x-x(0), in Sm(2)Fe(17)Z(x) are active for further diffusion and can migrate easily in Sm2Fe17 lattice.

The impedance as well as the resistance and reactance of the La0.75Sr0.25MnO3 manganite increase with increasing ac frequency due to the skin effect of the metal state below Curie temperature. The manganite La0.75Sr0.25MnO3 shows not only the colossal magnetoresistance effect but also the giant magnetoimpedance effect. For the giant magnetoimpedance, the magnetic field influences the impedance by affecting the penetration depth via the transverse permeability, whereas for the colossal magnetoresistance the magnetic field tends to align the local spins, leading to the decrease of the dc resistance via the interplay between a strong electron–phonon coupling and the double exchange effect of spin alignment on electron kinetic energy.

Nd 16 Fe 77- x Al x B 7 ( x = 0−7) sintered magnets with the maximum coercivity i H c = 20.5 kOe at x = 5 were obtained. The magnetic anisotropy fields of these magnets decrease with the addition of Al. The initial magnetizing field dependence of the coercivity for Nd 16 Fe 77- x Al x B 7 sintered magnets in the thermally demagnetized state was determined. The result clearly indicates that the Nd 16 Fe 77- x Al x B 7 sintered magnets are nucleation-hardened. The result of SEM shows that the grain boundary of the main phase in the Nd 16 Fe 77 B 7 magnet is clear, but not in the Nd 16 Fe 77- x Al x B 7 ( x = 5) magnet with a high coercivity of 20.5 kOe. The results of SEM for Nd 16 Fe 77- x Al x B 7 ( x = 5) magnet also show that there a new floss shaped phase is precipitated within the Nd-rich phase. With energy dispersive X-ray spectra, we determined the composition of this precipitation: Nd: Fe: Al = 76: 3.4: 20.6. The increase of coercivity i H c with Al can be attributed to better magnetic decoupling of the grains.

The structure and magnetic properties of RTi 1.1 Fe 10.9 alloys were investigated. X-ray analysis of the compounds revealed that RTi 1.1 Fe 10.9 alloys are of the tetragonal ThMn 12 structure. The lattice constants of these compounds were determined. The Curie temperature, the saturation magnetization at 1.5 and 300 K and the magnetic anisotropy fields at 77 and 300 K for RTi 1.1 Fe 10.9 were determined. The temperature dependences of the magnetization in the range of 1.5–300 K were measured for SmTi 1.1 Fe 10.9 and HoTi 1.1 Fe 10.9 . We found that R-Fe exchange interaction is ferromagnetic for light R and ferrimagnetic for heavy R. At 77 and 300 K, the compound RTi 1.1 Fe 10.9 (R = Sm, Y, Gd, Er, Ho) has an easy axis but it seems that TbTi 1.1 Fe 10.9 has an easy plane. The spin reorientation from planarto axial was observed for DyTi 1.1 Fe 10.9 at about 185 K. At the same time we found the FOMP for SmTi 1.1 Fe 10.9 , HoTi 1.1 Fe 10.9 and ErTi 1.1 Fe 10.9 . The initial critical field of FOMP at 77 K was determined.

The infrared and Raman spectra of α-Si:H:Cl films prepared by glow discharge were measured. The dependence of SiCl bonds on the preparation conditions of films was investigated. The results show that chlorine is incorporated only in monochloride bonding geometry at higher substrated temperature (400 C). And SiCl2 bonds were also formed at lower substrate temperature (200–300 C). The band at 795 cm−1 is related to the incorporation of oxygen and hydrogen rather than that of chlorine.

The structure and magnetocrystalline anisotropy of SmMo2Fe10 alloy were investigated. X-ray analysis revealed that SmMo2Fe10 has the tetragonal ThMn12 structure with parameters a = 8.6015 A , c = 4.7996 A , v = 355 A 3 . SmMo2Fe10 has an easy axis [001] from 78 to 293 k. The temperature dependence of the magnetization was measured. The Curie temperature was found to be 463 K. The temperature dependence of magnetic anisotropy field in the range 77 k – 300 k was determined. The value of magnetic anisotropy field at 300k is 45 kOe. It shows that SmMo2Fe10 based alloys can serve as permanent magnet materials.

Permanent magnets in the Nd16.5(Fe1−xCox)76.5B7 system were prepared by powder metallurgical methods. Magnetic hysteresis loops, with the magnetic field parallel and perpendicular to the aligning direction, were measured in the temperature range from 4.2 to 450 K. The magnetic anisotropy constants K1 and K2 of Nd2(Fe1−xCox)14B with 0≤x≤0.4 were determined by using aligned sintered magnets Nd16.5(Fe1‐xCox)76.5B7. The intrinsic coercive force iHc, magnetic anisotropy constants K1 and K2, and spin reorientation temperature decrease monotonically with increasing Co concentration.

All of GaAs-like and AlAs-like LO confined modes in (GaAs)n(AlAs)n short period superlattices are reported, to acknowledge, for the first time at room temperature and off-resonance conditions. It is shown that the Raman activity of confined LO modes is dependent on the scattering configuration. For the orientation x = (110), y = (110) and z = (001), the complete modes of confined LO phonons are observed in z(xx)z configuration, and no modes in z(xy)z configuration.

The composition dependence of Curie temperature, spin reorientation temperature and magnetic anisotropy field are investigated for Nd2 (Fe1-xTx)14B (T = Nb, Mo and Ga) alloys. The contribution of pinning to the magnetic hardening for NdFeNbB sintered magnets increases with the Nb addition. Precipitation has been found in NdFeNbB sintered magnet.

Sintered magnets (Nd1−xDyx)16.5(Fe0.85Co0.15)76.5B7 with 0≤x≤0.2 were prepared. In the temperature range 4.2–450 K, the magnetic hysteresis loops with parallel and perpendicular to aligned directions were measured applying a field up to 15 T. The temperature dependence of the permanent magnetic parameters for the magnets with various Dy concentrations was shown. Using a modified Sucksmith‐Thompson plot, the magnetic anisotropy fields of (Nd1−xDyx)2(Fe0.85Co0.15)14B were determined from the experimental results of sintered magnets. As Dy concentration increases, the anisotropy field of the magnets apparently increases, while the anisotropy field of the magnets decreases linearly. Substituting Dy for Nd, there is no effect on Curie temperature of the magnets, which was determined from that of SmCo‐type magnets, there exists a transition from nucleation dominated at a low magnetizing field to pinning dominated at a high magnetizing field.