Momentum profiles of the valence orbitals of methylpropane, also known as isobutane (CH3CH(CH3)CH3), have been studied by using a high resolution binary (e,2e) electron momentum spectrometer (EMS), at an impact energy of 1200 eV plus the binding energy, and using symmetric noncoplanar kinematics. The coincidence energy resolution of the EMS spectrometer is 0.95 eV full width at half-maximum. The experimental momentum profiles of the valence orbitals are compared with the theoretical momentum distributions calculated using Hartree–Fock (HF) and density functional theory (DFT) methods with the two basis sets of 6-31G and 6-311++G**. The B3LYP functionals are used for the DFT calculations. In general, the experimental momentum distributions are well described by the HF and DFT calculations. The pole strengths of the main ionization peaks from the orbitals in the inner valence are estimated.

Fe-SiO2 and Fe20Ni80-SiO2 granular solids have been prepared using a sol-gel method and investigated by X-ray diffractometry, Mossbauer spectroscopy and transmission electron microscopy. The magnetic properties were measured and the coercivity of these granular solid samples was found to be almost independent of temperature in the range 80-300 K. The effective magnetic anisotropy including shape anisotropy and strain anisotropy has been determined from the magnetizing curves of these granular solid samples using the law of approach to saturation. The obtained values of the effective magnetic anisotropy exceed 106 erg cm-3. The almost temperature-independent effective magnetic anisotropy can approximately explain the variation of Hc versus T for the granular solid samples. The shape anisotropy has been estimated assuming that the average axis ratio of the metal particles c/a is 1.2 and the strain anisotropy has been calculated from the effective anisotropy and the shape anisotropy. The magnitude of the strain anisotropy and the variation of the strain anisotropy with temperature are explained for the Fe-SiO2 and Fe20Ni80-SiO2 granular solid samples.

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In the present study magnetic and magnetostrictive properties of Tb(Fe1−xTx)2 (T=Mn, Ga) compounds were examined by magnetic measurement, Mössbauer, and x-ray study. Mössbauer study shows that the easy magnetization direction of the compounds may deviate slightly from the major axis of symmetry and the average isomer shift of the compounds decreases with increasing the x value, which was attributed to the charge transfer from 3d electrons of Mn atoms or 4p electrons of Ga atoms into the 3d band of Fe. It was also found from x-ray measurement that the spontaneous magnetostriction λ111 decreased due to Mn or Ga substitution, which can be understood on the basis of the single-ion model. The increase of the polycrystal magnetostriction λs due to Mn substitution was also found and can be ascribed to the increase of λ100, which may be caused by the filling of d bands due to substitution.

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