The samples Sr1–xCaxRuO3 (x = 0.0, 0.2, 0.6) have been synthesized by a solid state reaction, and characterized by the zero field cooled (ZFC), field cooled (FC) magnetic moments and the major hysteresis loops. The data have been analyzed within the framework of a generalized Preisach model, which includes thermal fluctuations, critical phenomenon, and temperature dependent distribution of free energy barriers. The model provides an excellent description of the experimental data, and the simulating results are in good agreement with the experiment results. All the ZFC/FC curves at different applied fields and all the major hysteresis loops at different temperatures can be replicated by the model with one set of parameters.

Ni-doped TiO2 anatase thin films were fabricated by reactive magnetron sputtering on SiO2 substrates. The doping and annealing effects on structure and magnetism for the films have been systematically investigated. The results show that ferromagnetism originated from the doped matrix and enhancement (suppression) of ferromagnetism is strongly correlated with the increase (decrease) of oxygen vacancies in TiO2.

Single-phase polycrystalline samples of La0.8-x Ndx Na0.2 MnO3 (x = 0.00, 0.05, 0.10, 0.15 and 0.20) were prepared by the sol–gel method. Investigations of Curie temperature and magnetic entropy change were carried out in the temperature range 240–340 K and magnetic field range 0–1 T. It was found that the Curie temperature TC decreases with increasing x, and that the maximum magnetic entropy change △S M , for x = 0.20, is 0.3692 J/mol K near the temperature 295 K. The results suggested that these perovskite manganites have some appropriate properties for a good candidate as magnetic refrigeration in the room temperature range.

A series of n-type Zn1-xCuxO (x = 0.02, 0.06, 0.10, and 0.12) films was prepared using direct current reactive magnetron sputtering. Magnetic measurements indicate that all the films are ferromagnetic at room temperature and the moment per Cu ion decreases with increasing copper concentration and nitrogen doping. The observed magnetic moment was 1.8

Zno.96Mn0.04O powder and thin films were prepared by standard solid-state reaction processes and radio-frequency (RF) magnetron sputtering. Magnetic measurements indicate that the powder is paramagnetic for temperatures above 3K, while the thin films annealed in vacuum are ferromagnetic at room temperature with a transition temperature of about 400K. The largest saturated magnetization (Ms) was found to be about 1.05