Research output: Contribution to journal › Article › peer-review
Experimental and Ab Initio Studies of Intrinsic Defects in "antizeolite" Borates with a Ba12(BO3)66+Framework and Their Influence on Properties. / Bekker, Tatyana B.; Inerbaev, Talgat M.; Yelisseyev, Alexander P. et al.
In: Inorganic Chemistry, Vol. 59, No. 18, 21.09.2020, p. 13598-13606.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Experimental and Ab Initio Studies of Intrinsic Defects in "antizeolite" Borates with a Ba12(BO3)66+Framework and Their Influence on Properties
AU - Bekker, Tatyana B.
AU - Inerbaev, Talgat M.
AU - Yelisseyev, Alexander P.
AU - Solntsev, Vladimir P.
AU - Rashchenko, Sergey V.
AU - Davydov, Alexey V.
AU - Shatskiy, Anton F.
AU - Litasov, Konstantin D.
N1 - Publisher Copyright: © 2020 American Chemical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/9/21
Y1 - 2020/9/21
N2 - The porous Ba12(BO3)66+ framework of the so-called "antizeolite"borates with channels along the c axis is capable of accommodating various guest anionic groups, e.g. [BO3]3-, [F2]2-, [F4]4-, and [(Li,Na)F4]3-. Taking as an example the Ba12(BO3)6[BO3][LiF4] crystal, we put forward the argument that the optical properties of "antizeolite"borates are strongly influenced by the degree of channel packing with anionic groups and, correspondingly, by the conjugated intrinsic defects. With the use of optical, electron-spin resonance, Raman spectroscopy, and ab initio calculations, it was shown that intrinsic defects largely impact the absorption of light in the visible and UV regions (the color of the bulk crystals can change from colorless to dark brown), absorption-edge position, dichroism, and other optical properties. The change in the optical absorption in the visible range is caused by the appearance of new states in the electronic structure inside the band gap, which are associated mainly with the presence of single and double F centers-fluorine vacancies that capture electrons-in [F4]4-, [F2]2-, and [LiF4]3- groups. The formation of F centers in the [F2]2- group is the most energetically favorable. It has been found that Ba12(BO3)6[BO3][LiF4] crystals are optically active gyrotropic with an isotropic point at 499 nm at 300 K and are of interest for practical application as narrow-band light filters.
AB - The porous Ba12(BO3)66+ framework of the so-called "antizeolite"borates with channels along the c axis is capable of accommodating various guest anionic groups, e.g. [BO3]3-, [F2]2-, [F4]4-, and [(Li,Na)F4]3-. Taking as an example the Ba12(BO3)6[BO3][LiF4] crystal, we put forward the argument that the optical properties of "antizeolite"borates are strongly influenced by the degree of channel packing with anionic groups and, correspondingly, by the conjugated intrinsic defects. With the use of optical, electron-spin resonance, Raman spectroscopy, and ab initio calculations, it was shown that intrinsic defects largely impact the absorption of light in the visible and UV regions (the color of the bulk crystals can change from colorless to dark brown), absorption-edge position, dichroism, and other optical properties. The change in the optical absorption in the visible range is caused by the appearance of new states in the electronic structure inside the band gap, which are associated mainly with the presence of single and double F centers-fluorine vacancies that capture electrons-in [F4]4-, [F2]2-, and [LiF4]3- groups. The formation of F centers in the [F2]2- group is the most energetically favorable. It has been found that Ba12(BO3)6[BO3][LiF4] crystals are optically active gyrotropic with an isotropic point at 499 nm at 300 K and are of interest for practical application as narrow-band light filters.
KW - NON-ENANTIOMORPHOUS CRYSTAL
KW - NONLINEAR-OPTICAL CRYSTAL
KW - ELECTRONIC-STRUCTURE
KW - GROWTH
KW - MORPHOLOGY
KW - DESIGN
UR - http://www.scopus.com/inward/record.url?scp=85091323830&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.0c01966
DO - 10.1021/acs.inorgchem.0c01966
M3 - Article
C2 - 32877188
AN - SCOPUS:85091323830
VL - 59
SP - 13598
EP - 13606
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 18
ER -
ID: 25606332