Author
H. Hata
Bio: H. Hata is an academic researcher from Osaka University. The author has contributed to research in topics: Europium & Crystal structure. The author has an hindex of 4, co-authored 6 publications receiving 100 citations.
Papers
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TL;DR: In this paper, the IR patterns of EuB4O7, Eu2B2O4, and eu2b2O5 were attributed to a three-dimensional network of BO4-tetrahedra, an endless chain of BO3 groups, and a B2O54− ion, respectively.
57 citations
TL;DR: In this paper, Europium and strontium orthoborate were crystallized in the rhombohedral system with two formula units in a cell of dimensions a R = 6.697 A, αR=85.17° for Eu3B2O6, and a R=6.695 A, αR =85.00° for Sr3B 2O6.
20 citations
TL;DR: The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c with a=9.069(1), c=12.542(2) A and Z=6.082 for 259 observed reflections with isotropic thermal parameters as discussed by the authors.
Abstract: The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c, with a=9.069(1), c=12.542(2) A and Z=6. The structure has been refined to R=0.082 for 259 observed reflections with isotropic thermal parameters. The borate contains isolated and planar triangle BO33− ions, the anions and Eu atoms being hexagonally packed along c. Each Eu atom is surrounded by 8 oxygens with Eu–O distances varying from 2.36 to 2.95 A. The interatomic distances between Eu atoms are 3.509–4.200 A for 8 nearest Eu neighbors and 4.831–5.450 A for 6 second-nearest Eu neighbors. The 6 nearest Eu neighbors with the interatomic distances of 3.509 and 3.778 A and the 4 second-nearest Eu neighbors with the Eu–O–Eu angle of 166.0° are effective for the magnetic exchange and superexchange interactions between Eu2+ ions, giving rise to ferromagnetism at low temperature.
12 citations
TL;DR: In this paper, Europium vanadites, containing bi-valent europium, were synthesized by reacting Eu2O3, V 2O3 and V.
12 citations
TL;DR: The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c with a=9.069(1), c=12.542(2) A and Z=6.082 for 259 observed reflections with isotropic thermal parameters.
Abstract: The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c, with a=9.069(1), c=12.542(2) A and Z=6. The structure has been refined to R=0.082 for 259 observed reflections with isotropic thermal parameters. The borate contains isolated and planar triangle BO33− ions, the anions and Eu atoms being hexagonally packed along c. Each Eu atom is surrounded by 8 oxygens with Eu–O distances varying from 2.36 to 2.95 A. The interatomic distances between Eu atoms are 3.509–4.200 A for 8 nearest Eu neighbors and 4.831–5.450 A for 6 second-nearest Eu neighbors. The 6 nearest Eu neighbors with the interatomic distances of 3.509 and 3.778 A and the 4 second-nearest Eu neighbors with the Eu–O–Eu angle of 166.0° are effective for the magnetic exchange and superexchange interactions between Eu2+ ions, giving rise to ferromagnetism at low temperature.
3 citations
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TL;DR: In this paper, a general approach based on the concept that the most appropriate and meaningful measure of the level of refrigeration is the product of entropy absorbed by the refrigerant at the cycle cold temperature, ΔS c, and the temperature span, ΔT, over which it is pumped is presented.
364 citations
TL;DR: In this article, the structural features of over 460 anhydrous oxoborates that are described in literature were analysed. And the Lewis acid strengths for all cations other than B 3+ that were found in these structures, using the valences of the cations and their determined average coordination numbers.
Abstract: The structural features of over 460 anhydrous oxoborates that are described in literature were analysed. Lewis acid strengths were calculated for all cations other than B 3+ that were found in these structures, using the valences of the cations and their determined average coordination numbers. From the observation of a restriction of the occurrence of complex polyborate anions to specific ranges of cation Lewis acid strength in existing oxoborate compounds, the Lewis base strengths of the complex polyborate anions (not of the oxygen ligands) were inferred, using the idea that is at the bottom of the valence matching principle, that in the most stable compounds the Lewis acid strength of the cation nearly equals the Lewis base strength of the anion. From this, general inherent rules for the occurrence of the miscellaneous polyborate anions with respect to the ratio cation: boron (A:B), the Lewis acid strength(s) L a of the cation(s) other than B 3+ and the cation radii were developed These rules offer the possibility for a prediction of the stoichiometry and the most probable polyborate structural group that will be adopted by a new anhydrous borate compound.
125 citations
TL;DR: In this paper, the luminescence properties of Eu(II)-borates and Eu 2+activated Sr-borates were studied, e.g. Sr 1− x Eu x B 2 O 4
98 citations
TL;DR: In this article, the luminescence properties of divalent europium complexes with crown ether, azacrown ether, N-pivot-azacrown- ether, and cryptand in methanol or water have been systematically investigated under UV irradiation.
85 citations
TL;DR: In this paper, a new oxoborate β -ZnB 4 O 7 was synthesized under high-pressure/high-temperature conditions from zinc oxide ZnO and boron oxide B 2 O 3 with a walker-type multianvil apparatus at 10.5 GPa and 1100 ǫ c.
60 citations