Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Li2B4O7 crystal structure in anharmonic approximation at 20, 200, 400 and 500 °C. / Sennova, Natalia; Bubnova, Rimma; Shepelev, Jurii; Filatov, Stanislav; Yakovleva, Olga.
в: Journal of Alloys and Compounds, Том 428, № 1-2, 31.01.2007, стр. 290-296.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Li2B4O7 crystal structure in anharmonic approximation at 20, 200, 400 and 500 °C
AU - Sennova, Natalia
AU - Bubnova, Rimma
AU - Shepelev, Jurii
AU - Filatov, Stanislav
AU - Yakovleva, Olga
PY - 2007/1/31
Y1 - 2007/1/31
N2 - Li2B4O7 crystal structure was studied at elevated temperatures and refined in anharmonic approximation: 20 °C, a = 9.475(3), c = 10.283(6) Å, 883 F(h k l), R = 0.015; 200 °C, a = 9.501(3), c = 10.275(6) Å, 826 F(h k l), R = 0.021; 400 °C, a = 9.535(3), c = 10.295(8) Å, 809 F(h k l), R = 0.022; and 500 °C, a = 9.550(3), c = 10.295(6) Å, 779 F(h k l), R = 0.029. B{single bond}O bond lengths were corrected in a view of O and B atomic vibrations. Refinement of anharmonic components of atomic temperature factors has revealed high asymmetry of Li thermal vibrations. The behaviour of tetraborate groups was studied. A stability of rigid B{single bond}O groups configuration was indicated, as in the case of β{single bond}CsB5O8, LiB3O5 and β-Na2B8O13, studied by us earlier. The boron-oxygen framework expands as a three-dimensional hinge; B{single bond}O{single bond}B and O{single bond}B{single bond}O angles inside tetraborate groups practically do not change, while B1{single bond}O1{single bond}B2 angles between the groups increase to 1.6° on heating up to 500 °C due to O1 atoms shifts letting Li atom to fall through oxygen atoms along c-axis causing the contraction in this direction.
AB - Li2B4O7 crystal structure was studied at elevated temperatures and refined in anharmonic approximation: 20 °C, a = 9.475(3), c = 10.283(6) Å, 883 F(h k l), R = 0.015; 200 °C, a = 9.501(3), c = 10.275(6) Å, 826 F(h k l), R = 0.021; 400 °C, a = 9.535(3), c = 10.295(8) Å, 809 F(h k l), R = 0.022; and 500 °C, a = 9.550(3), c = 10.295(6) Å, 779 F(h k l), R = 0.029. B{single bond}O bond lengths were corrected in a view of O and B atomic vibrations. Refinement of anharmonic components of atomic temperature factors has revealed high asymmetry of Li thermal vibrations. The behaviour of tetraborate groups was studied. A stability of rigid B{single bond}O groups configuration was indicated, as in the case of β{single bond}CsB5O8, LiB3O5 and β-Na2B8O13, studied by us earlier. The boron-oxygen framework expands as a three-dimensional hinge; B{single bond}O{single bond}B and O{single bond}B{single bond}O angles inside tetraborate groups practically do not change, while B1{single bond}O1{single bond}B2 angles between the groups increase to 1.6° on heating up to 500 °C due to O1 atoms shifts letting Li atom to fall through oxygen atoms along c-axis causing the contraction in this direction.
KW - Anharmonicity
KW - Anisotropy
KW - Crystal structure
KW - Thermal expansion
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=33845713885&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2006.03.049
DO - 10.1016/j.jallcom.2006.03.049
M3 - Article
AN - SCOPUS:33845713885
VL - 428
SP - 290
EP - 296
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
IS - 1-2
ER -
ID: 53950728