Abstract
Syntheses of single-crystal specimens and single-phase polycrystalline samples of are reported. Differential-thermal-analysis measurements indicate that this compound melts incongruently at 990 °C in air and at 970 °C in helium. Rietveld refinement of powder neutron diffraction data confirms the body-centered-tetragonal (I4/mmm) -type structure found earlier using x-ray techniques by Grande and Müller-Buschbaum. The planes are the same as in (tetragonal) , but the out-of--plane oxygens in the latter are replaced by Cl. The temperature dependences of the lattice parameters and thermal factors are reported; the tetragonal structure is retained from 300 K down to at least 25 K. Electrical-resistivity measurements exhibit essentially insulating behavior near room temperature, with ≃3000 Ω cm and ≃6.5× Ω cm.
- Received 23 August 1989
DOI:https://doi.org/10.1103/PhysRevB.41.1921
©1990 American Physical Society