Structure of KTiOAsO{sub 4} single crystals at 293 and 30 K

Journal Article · Sat May 15 04:00:00 EDT 2010 · Crystallography Reports

DOI:https://doi.org/10.1134/S1063774510030089· OSTI ID:22051205

Verin, I A; Sorokina, N I; Alekseeva, O A ^[1]; Tseitlin, M ^[2]; Roth, M ^[3]

---

1. Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)
2. Ariel University Center of Samaria (Israel)
3. Hebrew University of Jerusalem, Faculty of Science (Israel)

The unit cell parameters of KTiOPO{sub 4} and KTiOAsO{sub 4} single crystals are measured in the temperature range from room temperature to 20 K. It is found that the unit cell volume of the single crystals changes smoothly. With a decrease in temperature, the c parameter remains almost unchanged. In a certain temperature range, the linear temperature dependence of the a and b parameters is violated. An X-ray diffraction study of KTiOAsO{sub 4} single crystals is performed at T = 293 and 30 K. With a decrease in temperature, the electron density in the channels of the structure undergoes a redistribution, suggesting that at room temperature the state of the potassium ions is characterized by the dynamic and static disordering. The nonuniformity of the distribution of the electron density at the junctions of TiO{sub 6} octahedra and AsO{sub 4} tetrahedra is significantly enhanced in relation to that at the corresponding junctions in the KTiOPO{sub 4} structure. It has been experimentally established that the geometry of the tetrahedral anions makes a decisive contribution to the nonlinearity of KTiOAsO{sub 4} single crystals.

• OSTI ID: 22051205
• Journal Information: Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 3 Vol. 55; ISSN 1063-7745; ISSN CYSTE3
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARSENATES
DISTRIBUTION
ELECTRON DENSITY
GEOMETRY
MONOCRYSTALS
POTASSIUM COMPOUNDS
POTASSIUM IONS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0273-0400 K
TITANIUM COMPOUNDS
X-RAY DIFFRACTION