TY - JOUR

T1 - Crystal structure refinement and thermal properties of Ba2Lu5O2(BO3)5, a first example of barium rare-earth borate containing oxo-centered [OM4]+ tetrahedra

AU - Biryukov, Y.P.

AU - Bubnova, R.S.

AU - Shablinskii, A.P.

AU - Krzhizhanovskaya, M.G.

AU - Filatov, S.K.

PY - 2025/2/1

Y1 - 2025/2/1

N2 - Ba2Lu5O2(BO3)5 borate was prepared using a high-temperature multi-step solid-state reaction synthesis. Its crystal structure was first refined by the Rietveld refinement using X-ray powder diffraction data (at 25 °C). It crystallizes in the orthorhombic crystal system (Pbcn) with unit cell parameters a = 17.31669(3), b = 6.55523(3), c = 12.84820(5) Å, V = 1458.463(2) Å3, Z = 4. The structure can be described as a heteropolyhedral framework composed of distorted boron- and lutetium-oxygen polyhedra. The Ba2+ atoms are in cavities of the framework. A static disorder exists in the structure due to an occupation of the M(1) and M(2) (M = Ba2+, Lu3+) sites in parallel by the Ba2+ and Lu3+ atoms. There are vertex- and edge-sharing oxo-centered [O(7)M4]n+ tetrahedra in the structure that form infinite [O2M5]n+ isolated single chains elongated through the c axis. A thermal behavior of Ba2Lu5O2(BO3)5 was investigated by high-temperature X-ray powder diffraction over the temperature range of 25–1000 °C. No phase transitions occur in the range investigated. Degree of the thermal expansion anisotropy decreases with the temperature increase (Δmax = 0.52 at 25 °C and 0.16 at 1000 °C), while the volume expansion increases (αV = 26.8 and 36.8 × 10−6 °C−1 at 25 and 1000 °C, respectively). The anisotropy of the expansion is described in comparison with the crystal structure of Ba2Lu5O2(BO3)5.

AB - Ba2Lu5O2(BO3)5 borate was prepared using a high-temperature multi-step solid-state reaction synthesis. Its crystal structure was first refined by the Rietveld refinement using X-ray powder diffraction data (at 25 °C). It crystallizes in the orthorhombic crystal system (Pbcn) with unit cell parameters a = 17.31669(3), b = 6.55523(3), c = 12.84820(5) Å, V = 1458.463(2) Å3, Z = 4. The structure can be described as a heteropolyhedral framework composed of distorted boron- and lutetium-oxygen polyhedra. The Ba2+ atoms are in cavities of the framework. A static disorder exists in the structure due to an occupation of the M(1) and M(2) (M = Ba2+, Lu3+) sites in parallel by the Ba2+ and Lu3+ atoms. There are vertex- and edge-sharing oxo-centered [O(7)M4]n+ tetrahedra in the structure that form infinite [O2M5]n+ isolated single chains elongated through the c axis. A thermal behavior of Ba2Lu5O2(BO3)5 was investigated by high-temperature X-ray powder diffraction over the temperature range of 25–1000 °C. No phase transitions occur in the range investigated. Degree of the thermal expansion anisotropy decreases with the temperature increase (Δmax = 0.52 at 25 °C and 0.16 at 1000 °C), while the volume expansion increases (αV = 26.8 and 36.8 × 10−6 °C−1 at 25 and 1000 °C, respectively). The anisotropy of the expansion is described in comparison with the crystal structure of Ba2Lu5O2(BO3)5.

KW - Barium-lutetium borate

KW - Crystal structure

KW - Oxoborate

KW - Rietveld refinement

KW - Thermal expansion

UR - https://www.mendeley.com/catalogue/b6f127cf-4149-3602-b8bb-ee6a5ab0aecc/

U2 - 10.1016/j.inoche.2024.113717

DO - 10.1016/j.inoche.2024.113717

M3 - Article

VL - 172

JO - Inorganic Chemistry Communication

JF - Inorganic Chemistry Communication

SN - 1387-7003

M1 - 113717

ER -