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Updated: Aug 30, 2026

Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition
Published on: July 26, 2016
Phase transitions in KTP isostructures: correlation between structure and Tc in germanium-doped RbTiOPO4
Stefan T Norberg1, Joacim Gustafsson, Bengt-Erik Mellander
1Materials and Surface Chemistry, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. stn@inoc.chalmers.se
Abstract:
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(0.125)Ti(0.875))(Ge(0.225)Ti(0.775))O(2)(PO(4))(2) (GeRTP#2), have been structurally characterized from X-ray diffraction data at room temperature. In addition, a third structure, Rb(2)(TiO)(2)(PO(4))(2) (RTP), has been reinvestigated. The exchange of titanium for germanium results in a less distorted octahedral coordination around the two crystallographically independent titanium sites. Additionally, rubidium split-cation positions have been found in these doped RTP crystals. Dielectric measurements show that the phase-transition temperature, T(c), decreases with increasing germanium concentration, and a direct correlation between the room-temperature split of the rubidium cations and T(c) has been discovered. General trends regarding the relationship between the room-temperature structures of KTP-like compounds and their T(c) values are discussed.
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