TY - JOUR

T1 - The first silver bis­muth borate, AgBi2B5O11

AU - Волков, Сергей

AU - Чаркин, Дмитрий

AU - Бубнова, Римма Сергеевна

AU - Поволоцкий, Алексей Валерьевич

AU - Арсентьев, Максим

AU - Кржижановская, Мария Георгиевна

AU - Стефанович, Сергей

AU - Уголков, Валерий Леонидович

AU - Куриленко, Людмила

PY - 2019/7

Y1 - 2019/7

N2 - The first silver bismuth borate, AgBi 2B 5O 11 (silver dibismuth pentaborate), has been prepared via glass crystallization in the Ag 2O–Bi 2O 3–B 2O 3 system and characterized by single-crystal X-ray diffraction. Its structure is derived from that of centrosymmetric Bi 3B 5O 12 by ordered substitution of one Bi 3+ ion for Ag +, which results in the disappearance of the mirror plane and inversion centre. Second harmonic generation (SHG) measurements confirm the acentric crystal structure. It is formed by [Bi 2B 5O 11] ∞ layers stretched along c and comprised of vertex-sharing B 5O 10 and BiO 3 groups which incorporate the Ag + cations. The new compound was characterized by thermal analysis, high-temperature powder X-ray diffraction, and vibrational and UV–Vis–NIR (near infrared) spectroscopy. Its thermal expansion is strongly anisotropic due to the presence of rigid B 5O 10 groups aligned in a parallel manner. The minimal value is observed along their axis [parallel to c, α c = 3.1 (1) × 10 −6 K −1], while maximal values are observed in the ab plane [α a = 20.4 (2) and α b = 7.8 (2) × 10 −6 K −1]. Upon heating, AgBi 2B 5O 11 starts to decay above 684 K due to partial reduction of silver; incongruent melting is observed at 861 K. According to density functional theory (DFT) band-structure calculations, the new compound is a semiconductor with an indirect energy gap of 3.57 eV, which agrees with the experimental data (absorption onset at 380 nm).

AB - The first silver bismuth borate, AgBi 2B 5O 11 (silver dibismuth pentaborate), has been prepared via glass crystallization in the Ag 2O–Bi 2O 3–B 2O 3 system and characterized by single-crystal X-ray diffraction. Its structure is derived from that of centrosymmetric Bi 3B 5O 12 by ordered substitution of one Bi 3+ ion for Ag +, which results in the disappearance of the mirror plane and inversion centre. Second harmonic generation (SHG) measurements confirm the acentric crystal structure. It is formed by [Bi 2B 5O 11] ∞ layers stretched along c and comprised of vertex-sharing B 5O 10 and BiO 3 groups which incorporate the Ag + cations. The new compound was characterized by thermal analysis, high-temperature powder X-ray diffraction, and vibrational and UV–Vis–NIR (near infrared) spectroscopy. Its thermal expansion is strongly anisotropic due to the presence of rigid B 5O 10 groups aligned in a parallel manner. The minimal value is observed along their axis [parallel to c, α c = 3.1 (1) × 10 −6 K −1], while maximal values are observed in the ab plane [α a = 20.4 (2) and α b = 7.8 (2) × 10 −6 K −1]. Upon heating, AgBi 2B 5O 11 starts to decay above 684 K due to partial reduction of silver; incongruent melting is observed at 861 K. According to density functional theory (DFT) band-structure calculations, the new compound is a semiconductor with an indirect energy gap of 3.57 eV, which agrees with the experimental data (absorption onset at 380 nm).

KW - bismuth borate

KW - crystal structure

KW - silver borate

KW - thermal expansion

UR - http://www.scopus.com/inward/record.url?scp=85068252092&partnerID=8YFLogxK

U2 - 10.1107/S2053229619007605

DO - 10.1107/S2053229619007605

M3 - Article

VL - C75

SP - 910

EP - 918

JO - Acta Crystallographica Section C-Structural Chemistry

JF - Acta Crystallographica Section C-Structural Chemistry

SN - 2053-2296

IS - 7

ER -