Pergamon Materials Research Bulletin, Vol. 29, No. 12, pp. 1321-1331, 1994 Copyright © 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0025-5408/94 $6.00 + .00 0025-5408(94)00092-1 STUDY OF THE CRYSTALLINE QUALITY OF CZOCHRALSKI GROWN BARIUM LITHIUM FLUORIDE SINGLE CRYSTALS S. L. Baldochi, V. L. Mazzocchi, C. B. R. Parente and S. P. Morato INSTITUTO DE PESQUISAS ENERGI~TICAS E NUCLEARES - IPEN Caixa Postal 11049 - CEP 05422-970 - Sio Paulo - SP - Brasil (Received June 7, 1994; Refereed) ABSTRACT The influence of crystallographic orientation and rotation rate on the crystalline quality of Czochralski grown BaLiF 3 crystals have been studied by neutron diffraction techniques. Analysis of the mosaicity of crystals showed that growth in the <111> direction with a flat interface resulted in crystals with good optical and crystalline quafity. However, growth in the <100> direction with flat interface produced a low degree of optical quality but still with good crystallinity. MATERIALS INDEX: perovskite, fluorides, barium, lithium. In¢oduction Recent investigations have shown that crystals with cubic perovskite-like structures are very interesting active media for laser applications. Examples of tunable 3+ + lasers can be obtained with Cr doped KZnF 3 and Pb doped KMgF 3 crystals [1,2]. + 2+ BaLiF 3 is an inverse perovskite and a potential laser crystal when doped with Pb 2 , Ni and Co 2+. The optical properties of these crystals were investigated [3, 4] and their performance as laser media was shown to be dependent on their optical and crystalline quality, which are associated with the preparation conditions and growth process. Recently, Baldochi and Gesland [5] studied the conditions of synthesis and Czochralski growth of BaLiF 3 crystals that produce a good degree of optical quality. In this work we studied the influence of the growth process in the crystalline quality of the Czochralski grown BaLiF 3 single crystals. During the growth of a single crystal, it is possible that more than one crystalline domain is formed. In general, the orientations of the dom ain.q are very close to one 1321