Part I. Preparation of lanthanide single crystals. Part II. Elastic moduli and thermal expansion of lutetium single crystals from 4.2 to 300°K

A study has been made on three methods that could be used in preparing large single crystals, approximately 1.25 cm (0.500 inch) in diameter and in length, of the light lanthanide metals, praseodymium and neodymium, and the heavy lanthanide metal, lutetium. The strain-anneal process with its variations has been successfully applied in preparing lutetium crystals. The electron-beam-floating-zone technique and the crystallographic tansformation method have shown the greatest promise for praseodymium and neodymium. The adiabatic elastic moduli and linear thermal expansion coefficients of lutetium single crystals have been calculated from 4.2 to 300 degreesK, from position technique has been employed to determine transit times, and a linear-variable-differential-transformer dilatometer to determine densities. The Debye characteristic temperature and the bulk elastic properties (Youn's modulus, Poisson's ration, the shear modulus, and the bulk modulus) have been calculated from the elastic moduli.