Preparation and crystal structure of metallic 248Cm, 249Bk and 249Cf

Using reduction of TPE oxides with thorium and lanthanum and the following distillation the samples of 248Cm, 249Bk, 249Cf rare actinoid metals with the mass from 0.7 to 0.1 mg in the form of micron layers on tantalum and quartz substrates are prepared. Metal yield during reduction constituted 99.85 and 84% respectively. All three metals at room temperature have a binary hcp crystal lattice with spacing decreasing from Cm to Cf. Also detected is fcc structure of metallic Cm (a=0.4933nm) high-temperature modification. Oxidation of prepared metals is studied. Thermal expansion coefficients of 248Cm and 249Bk in the 93-300K temperature range are determined