Growth of pure and doped KMgF3 single crystals

The preparation of pure and doped KMgF3 single crystals using the Czochralski and Bridgman methods is described. The crystals were obtained using a home-made Czochralski-type device that allows also the growth of single crystals by the vertical Bridgman method (which we used mainly for the preparation of doped single crystals). The starting materials were KF or KHF2, MgF2 and, for the preparation of Mn2+ or Ni2+ doped crystals, KMnF3 or KNiF3. The crystals were produced using pulling rates of 4-5 mm h(-1) and a rotation of 4-6 rpm. We have obtained good quality, transparent, both pure and Mn2+ or Ni2+ doped KMgF3 single crystals of approximately 1 cm in diameter and 7.5-8.0 cm long. The transmission spectrum (in the range of 200-800 nm) and the absorption spectrum (in the range of 400-5000 cm(-1)) of the pure single crystals are given.