Growth and properties of potassium holmium double tungstate KHo(WO4)(2)

Potassium holmium tungstate KHo(WO4)(2) crystal, as other tungstates, shows the high temperature irreversible structural phase transition. Owing to th is. KHo(WO4)(2) single crystals were grown due to spontaneous crystallisati on with use of the High Temperature Solution Growth technique, which allows to lower the temperature of crystallisation below the temperature of the p hase transition. K2W2O7 was used as a solvent. It provides a very wide temp erature range of crystallisation and does not introduce additional impuriti es into the melt. The starring flux contained 20 mol% of KHo(WO4), dissolve d in K2W2O7. It was found that potassium holmium double tungstate is pleoch roic. The two different optical spectra: one spectrum for electrical vector of linearly polarised light parallel to optical Y axis (main spectrum) and second one for electrical vector perpendicular to Y axis were measured.