Two new phosphate langbeinites, Rb2YbTi(PO4)3 and Rb2Yb0.32Ti1.68(PO4)3, investigated at 293 and 150 K.

The rubidium ytterbium titanium phosphates Rb2YbTi(PO4)3, (I), and Rb2Yb(0.32)Ti(1.68)(PO4)3, (II), have been structurally characterized from X-ray data collected at both 293 and 150 K.

Phase transitions in KTP isostructures: correlation between structure and Tc in germanium-doped RbTiOPO4.

Crystals of germanium-doped rubidium titanyl phosphate, Rb(2)(Ti)(Ge(0.121)Ti(0.879))O(2)(PO(4))(2) (GeRTP#1) and Rb(2)(Ge(0.