GROWTH AND MICROHARDNESS STUDIES ON NH4SB3F10 SINGLE-CRYSTALS

Ammonium fluoride NH4F and antimony trifluoride SbF3 form many stoichi ometric compounds, such as NH4SbF4, (NH4)2SbF5, NH4Sb2F7, (NH4)3Sb2F9, NH4Sb3F10, etc. Since (NH4)2SbF5 exhibits superionic conductivity and undergoes phase transitions, an attempt has been made to grow other s toichiometric compounds of this group. In this report, we deal with th e growth and microhardness studies of NH4Sb3F10, single crystals. Crys tals of size 60 x 25 x 35 mm3 were grown in a period of two months. Mi crohardness studies have been carried out using a Vickers diamond pyra mid indenter. To study the anisotropy of this material, specimens cut in different orientations such as (001), (010), (100), (101), (101BAR) have been subjected to microhardness studies. The results show strong anisotropy in the work-hardening coefficient for different orientatio ns. This anisotropy is explained on the basis of a plastic deformation model.