Preparation and Properties of Ca2 V 2 O 7 Single Crystals

Abstract

Ca2V2O7 single crystals were prepared by flux growth technique from normalCaO‐V2O5‐K2O melts. Only small crystals could be produced because of stresses developed on cooling. The crystals were indexed in the triclinic system with P1 symmetry, x‐ray powder diffraction patterns were in agreement with published data. DTA and DSC measurements on the Ca2V2O7 samples were in agreement with previous phase studies. No phase transformations were observed up to ∼600°C. Thermal expansion coefficient false(97×10−7 normalcm/normalcm°Cfalse) over this temperature range was essentially linear. Electrical resistivity and dielectric data up to 600°C showed excellent insulation and breakdown characteristics. Ferroelectric behavior was, however, not observed for the crystals.

Superstructure ZrV2O7nanofibres: thermal expansion, electronic and lithium storage properties

“…55 The two periods can be linearly fitted with a different slope, indicating their conformation to the typical Mott law. Analogous to the reported Ca 2 V 2 O 7 single crystal, 56 the conduction mechanism should be attributed only to the electron conduction that stems from the vanadium ions at lower temperatures (o102 1C). And the addition of predominantly ionic conduction by mobile Zr 4+ or O 2À ions above 102 1C is the reason for the steeper slope shown in Fig.…”