A novel birefrmgent a-BaB2O4 crystal with 40mm in diameter, 35mm in height has been grown successfully in our laboratory by Czochralski method. The proportion of B203 and BaO of starting material, crystal cracking and the transmission spectrum of a-BaB2O4 crystal have been briefly analyzed.

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Robust ferromagnetic ordering at, and well above room temperature is observed in pure transparent MgO thin films (<170 nm thick) deposited by three different techniques. Careful study of the wide scan x-ray photoelectron spectroscopy rule out the possible presence of any magnetic contaminants. In the magnetron sputtered films, we observe magnetic phase transitions as a function of film thickness. The maximum saturation magnetization of 5.7 emu/cm3 is measured on a 170 nm thick film. The films above 500 nm are found to be diamagnetic. Ab initio calculations suggest that the ferromagnetism is mediated by cation vacancies.