Unique crystallization and formation of nonlinear optical (Na,K)NbO 3 phases in (Na,K)NbGeO5 glasses

K. Narita; Y. Takahashi; Y. Benino; T. Fujiwara; T. Komatsu

doi:10.1016/j.optmat.2003.10.003

Unique crystallization and formation of nonlinear optical (Na,K)NbO ₃ phases in (Na,K)NbGeO₅ glasses

K. Narita, Y. Takahashi, Y. Benino, T. Fujiwara, T. Komatsu

Research output: Contribution to journal › Article › peer-review

29 Citations (Scopus)

Abstract

Crystalline phases and second-order optical nonlinearities in crystallized glasses of (Na,K)NbGeO₅ (i.e., xNa₂O·(25-x)K ₂O·25Nb₂O₅·50GeO₂) are examined. The molar volume of the glasses decreases with increasing Na ₂O content, indicating that the glass structure of NaNbGeO ₅ glass is more compact compared with KNbGeO₅ glass. The optical basicity of the glasses is 0.94-0.95, implying that chemical bonds among constituents ions are basically very ionic. (Na,K)NbGeO₅ glasses exhibit a unique crystallization depending on the Na₂O/K₂O ratio. The main crystalline phase in crystallized NaNbGeO₅ glass is the NaNbGeO₅ phase. KNbGeO₅ glass shows a prominent bulk nanocrystallization giving nanocrystals of the K_3.8Nb ₅Ge₃O_20.4 phase. A glass with the composition of K_3.8Nb₅Ge₃O_20.4 also shows a bulk nanocrystallization. The crystallized glasses with K_3.8Nb ₅Ge₃O_20.4 and NaNbGeO₅ crystalline phases do not show a second harmonic generation (SHG) at room temperature. The nonlinear optical (Na,K)NbO₃ phases showing a SHG are formed at the surface (∼5 μm) of crystallized glasses with x=15 and 20, giving an orientation of the (110) plane. The present study suggests the presence of mixed-alkali effect in the crystallization behavior of (Na,K)NbGeO₅ glasses.

Original language	English
Pages (from-to)	393-400
Number of pages	8
Journal	Optical Materials
Volume	25
Issue number	4
DOIs	https://doi.org/10.1016/j.optmat.2003.10.003
Publication status	Published - May 2004
Externally published	Yes

Keywords

(Na,K)NbO
Nanocrystallization
Optical basicity
Second harmonic generation

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Computer Science(all)
Atomic and Molecular Physics, and Optics
Spectroscopy
Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry
Electrical and Electronic Engineering

Access to Document

10.1016/j.optmat.2003.10.003

Cite this

@article{b6d8c9cf369a41d1ac7239341aa6a115,

title = "Unique crystallization and formation of nonlinear optical (Na,K)NbO 3 phases in (Na,K)NbGeO5 glasses",

abstract = "Crystalline phases and second-order optical nonlinearities in crystallized glasses of (Na,K)NbGeO5 (i.e., xNa2O·(25-x)K 2O·25Nb2O5·50GeO2) are examined. The molar volume of the glasses decreases with increasing Na 2O content, indicating that the glass structure of NaNbGeO 5 glass is more compact compared with KNbGeO5 glass. The optical basicity of the glasses is 0.94-0.95, implying that chemical bonds among constituents ions are basically very ionic. (Na,K)NbGeO5 glasses exhibit a unique crystallization depending on the Na2O/K2O ratio. The main crystalline phase in crystallized NaNbGeO5 glass is the NaNbGeO5 phase. KNbGeO5 glass shows a prominent bulk nanocrystallization giving nanocrystals of the K3.8Nb 5Ge3O20.4 phase. A glass with the composition of K3.8Nb5Ge3O20.4 also shows a bulk nanocrystallization. The crystallized glasses with K3.8Nb 5Ge3O20.4 and NaNbGeO5 crystalline phases do not show a second harmonic generation (SHG) at room temperature. The nonlinear optical (Na,K)NbO3 phases showing a SHG are formed at the surface (∼5 μm) of crystallized glasses with x=15 and 20, giving an orientation of the (110) plane. The present study suggests the presence of mixed-alkali effect in the crystallization behavior of (Na,K)NbGeO5 glasses.",

keywords = "(Na,K)NbO, Nanocrystallization, Optical basicity, Second harmonic generation",

author = "K. Narita and Y. Takahashi and Y. Benino and T. Fujiwara and T. Komatsu",

note = "Funding Information: This work was supported with a Grant of Nippon Sheet Glass Foundation for Materials Science and Engineering, and a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan, and the 21st Century Center of Excellence (COE) Program in Nagaoka University of Technology.",

year = "2004",

month = may,

doi = "10.1016/j.optmat.2003.10.003",

language = "English",

volume = "25",

pages = "393--400",

journal = "Optical Materials",

issn = "0925-3467",

publisher = "Elsevier",

number = "4",

}

TY - JOUR

T1 - Unique crystallization and formation of nonlinear optical (Na,K)NbO 3 phases in (Na,K)NbGeO5 glasses

AU - Narita, K.

AU - Takahashi, Y.

AU - Benino, Y.

AU - Fujiwara, T.

AU - Komatsu, T.

N1 - Funding Information: This work was supported with a Grant of Nippon Sheet Glass Foundation for Materials Science and Engineering, and a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan, and the 21st Century Center of Excellence (COE) Program in Nagaoka University of Technology.

PY - 2004/5

Y1 - 2004/5

N2 - Crystalline phases and second-order optical nonlinearities in crystallized glasses of (Na,K)NbGeO5 (i.e., xNa2O·(25-x)K 2O·25Nb2O5·50GeO2) are examined. The molar volume of the glasses decreases with increasing Na 2O content, indicating that the glass structure of NaNbGeO 5 glass is more compact compared with KNbGeO5 glass. The optical basicity of the glasses is 0.94-0.95, implying that chemical bonds among constituents ions are basically very ionic. (Na,K)NbGeO5 glasses exhibit a unique crystallization depending on the Na2O/K2O ratio. The main crystalline phase in crystallized NaNbGeO5 glass is the NaNbGeO5 phase. KNbGeO5 glass shows a prominent bulk nanocrystallization giving nanocrystals of the K3.8Nb 5Ge3O20.4 phase. A glass with the composition of K3.8Nb5Ge3O20.4 also shows a bulk nanocrystallization. The crystallized glasses with K3.8Nb 5Ge3O20.4 and NaNbGeO5 crystalline phases do not show a second harmonic generation (SHG) at room temperature. The nonlinear optical (Na,K)NbO3 phases showing a SHG are formed at the surface (∼5 μm) of crystallized glasses with x=15 and 20, giving an orientation of the (110) plane. The present study suggests the presence of mixed-alkali effect in the crystallization behavior of (Na,K)NbGeO5 glasses.

AB - Crystalline phases and second-order optical nonlinearities in crystallized glasses of (Na,K)NbGeO5 (i.e., xNa2O·(25-x)K 2O·25Nb2O5·50GeO2) are examined. The molar volume of the glasses decreases with increasing Na 2O content, indicating that the glass structure of NaNbGeO 5 glass is more compact compared with KNbGeO5 glass. The optical basicity of the glasses is 0.94-0.95, implying that chemical bonds among constituents ions are basically very ionic. (Na,K)NbGeO5 glasses exhibit a unique crystallization depending on the Na2O/K2O ratio. The main crystalline phase in crystallized NaNbGeO5 glass is the NaNbGeO5 phase. KNbGeO5 glass shows a prominent bulk nanocrystallization giving nanocrystals of the K3.8Nb 5Ge3O20.4 phase. A glass with the composition of K3.8Nb5Ge3O20.4 also shows a bulk nanocrystallization. The crystallized glasses with K3.8Nb 5Ge3O20.4 and NaNbGeO5 crystalline phases do not show a second harmonic generation (SHG) at room temperature. The nonlinear optical (Na,K)NbO3 phases showing a SHG are formed at the surface (∼5 μm) of crystallized glasses with x=15 and 20, giving an orientation of the (110) plane. The present study suggests the presence of mixed-alkali effect in the crystallization behavior of (Na,K)NbGeO5 glasses.

KW - (Na,K)NbO

KW - Nanocrystallization

KW - Optical basicity

KW - Second harmonic generation

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U2 - 10.1016/j.optmat.2003.10.003

DO - 10.1016/j.optmat.2003.10.003

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SN - 0925-3467

VL - 25

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EP - 400

JO - Optical Materials

JF - Optical Materials

IS - 4

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