Synthesis and Characterization of the High-Pressure Nickel Borate γ-NiB4O7.
γ-NiB4O7was synthesized in a high-pressure/high-temperature experiment at 5 GPa and 900 °C. The single-crystal structure analysis yielded the following results: space group P6522 (No. 179), a = 425.6(2), c = 3490.5(2) pm, V = 0.5475(2) nm3, Z = 6, and Flack parameter x = -0.010(5). Second harmonic generation measurements confirmed the acentric crystal structure. Furthermore, γ-NiB4O7was characterized via vibrational as well as single-crystal electronic absorption spectroscopy, magnetic measurements, high-temperature X-ray diffraction, differential scanning calorimetry, and thermogravimetry. Density functional theory-based calculations were performed to facilitate band assignments to vibrational modes and to evaluate the elastic properties and phase stability of γ-NiB4O7.
Institut für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
Martin K
MK
Schmitt
Oliver
http://orcid.org/0000-0002-9480-3888
O
Janka
Oliver
O
Niehaus
Thomas
T
Dresselhaus
Rainer
R
Pöttgen
Institut für Anorganische Chemie, Universität Regensburg , Universitätsstraße 31, 93040 Regensburg, Germany.
Florian
F
Pielnhofer
Institut für Materials Resource Management, Universität Augsburg , Universitätsstraße 1, 86135 Augsburg, Germany.
Richard
R
Weihrich
Department of Crystallography, St. Petersburg State University , University Embankment 7/9, 199034 St. Petersburg, Russia.
Maria
M
Krzhizhanovskaya
Department of Crystallography, St. Petersburg State University , University Embankment 7/9, 199034 St. Petersburg, Russia.
Stanislav
S
Filatov
Department of Crystallography, St. Petersburg State University , University Embankment 7/9, 199034 St. Petersburg, Russia.|Grebenshchkov Institute of Silicate Chemistry, Russian Academy of Sciences , Makarov Embankment 2, 199034 St. Petersburg, Russia.
Rimma
R
Bubnova
Institut für Geowissenschaften, Universität Frankfurt , Altenhöferallee 1, 60438 Frankfurt/Main, Germany.
Lkhamsuren
L
Bayarjargal
Institut für Geowissenschaften, Universität Frankfurt , Altenhöferallee 1, 60438 Frankfurt/Main, Germany.
Björn
B
Winkler
Institut für Anorganische Chemie, Universität Bonn , Gerhard-Domagk-Straße 1, 53121 Bonn, Germany.
Robert
R
Glaum
Institut für Allgemeine, Anorganische und Theoretische Chemie, Universität Innsbruck , Innrain 80-82, 6020 Innsbruck, Austria.
Hubert
http://orcid.org/0000-0002-2098-6087
H
Huppertz