Inclusion Defects in Ca（BO2）2 Crystals Grown by Czochralski Method

doi:10.16553/j.cnki.issn1000-985x.2025.0072

Abstract

Abstract: Calcium metaborate （Ca（BO₂）₂） crystal is a kind of deep ultraviolet birefringent crystal with great development potential and broad application prospect because of its short ultraviolet transmission cutoff， high ultraviolet transmittance and large birefringence index. However， inclusion defects easily occur during the process of crystal growth， which seriously impact the application of crystals. In this study， Ca（BO₂）₂ crystals were grown using the Czochralski method， and test samples were prepared. The morphology， size， distribution， and composition of the inclusions were investigated using a polarizing microscope， scanning electron microscopy， and Raman spectroscopy. The formation mechanism of the inclusions was analyzed in conjunction with the crystal growth process， and strategies for eliminating inclusions were explored. The result of research shows that the inclusions in Ca（BO₂）₂ crystals are gaseous in nature， originating from gas molecules dissolved in the melt， and appear in the form of “spherical” “linear” and “tadpole-like” shapes. The formation of these inclusions is determined by the interplay between the crystal growth rate and the gas bubble diffusion rate. The inclusions can be completely eliminated by overheating the melt， increasing the temperature gradient at the growth interface， reducing the growth rate， and increasing the crystal growth rotation speed.

Key words: Ca（BO₂）₂ crystal; Czochralski method; inclusion; growth rate; temperature gradient; solute boundary layer

CLC Number:

O77⁺1

LI Shifeng, YANG Jinfeng, HUANG Yunqi, ZHANG Bo, LIU Ziqi, SUN Jun, PAN Shilie. Inclusion Defects in Ca（BO₂）₂ Crystals Grown by Czochralski Method[J]. Journal of Synthetic Crystals, 2025, 54(9): 1501-1508.

Figures/Tables 6

Fig.1 Images of CB2 crystal and schematic diagram of inclusion distribution. （a） The crystal with fewer inclusions；（b） the crystal with severe inclusions；（c） cellular interface at the bottom of the crystal；（d） the schematic diagram of inclusion distribution observed on the （010） plane in the crystal

Fig.2 Morphology of inclusions observed on（001） plane

Fig.3 Inclusions in CB2 crystal. （a） SEM image；（b） EDS spectra sampling locations

Table 1 EDS energy spectroscopy analysis results

Site	Mass fraction/%
Site	Ca	B	O
Spectrum 7	12.4	82.7	4.9
Spectrum 9	21.7	34.1	44.1
Spectrum 10	14.5	57.9	27.5

Fig.4 Comparison of Raman spectra of CB2 crystals with and without inclusions

Fig.5 Transmission spectrum of CB2 crystals without inclusion defect

References 24

[1]	YAN F， WANG C， YAN Y Y， et al. Polarization-sensitive optical coherence tomography for renal tumor detection in ex vivo human kidneys［J］. Optics and Lasers in Engineering， 2024， 173： 107900.
[2]	WANG J W， DONG L， CHEN H G， et al. Birefringence measurement of biological tissue based on polarization-sensitive digital holographic microscopy［J］. Applied Physics B， 2018， 124（12）： 240.
[3]	雎　洲，王　晨，王凯辉，等. 32.768 Tbit/s净速率1 000 km长少模光纤波分复用系统［J］. 光学学报， 2023， 43（10）： 1006004.
	JU Z， WANG C， WANG K H， et al. 1000-km-long few-mode fiber wavelength division multiplexing transmission system with net rate of 32.768 Tbit/s［J］. Acta Optica Sinica， 2023， 43（10）： 1006004 （in Chinese）.
[4]	BADIEYAN S， ABEDINI M， RAZZAGHI M， et al. Polarimetric imaging-based cancer bladder tissue's detection： a comparative study of bulk and formalin-fixed paraffin-embedded samples［J］. Photodiagnosis and Photodynamic Therapy， 2023， 44： 103698.
[5]	TUDI A， HAN S J， YANG Z H， et al. Potential optical functional crystals with large birefringence： recent advances and future prospects［J］. Coordination Chemistry Reviews， 2022， 459： 214380.
[6]	蔡燕民，王向朝，黄惠杰. 用于ArF光刻机偏振照明系统的沃拉斯顿棱镜的设计［J］. 中国激光， 2014， 41（6）： 616002.
	CAI Y M， WANG X Z， HUANG H J. Design of Wollaston prism used for polarization illumination system in ArF lithography tool［J］. Chinese Journal of Lasers， 2014， 41（6）： 616002 （in Chinese）.
[7]	SATO T. Impact of polarization on an attenuated phase shift mask with ArF hyper-numerical aperture lithography［J］. Nanolithography， MEMS， and MOEMS， 2006， 5（4）： 043001.
[8]	DODGE M J. Refractive properties of magnesium fluoride［J］. Applied Optics， 1984， 23（12）： 1980. PMID
[9]	ZHOU G Q， XU J， CHEN X D， et al. Growth and spectrum of a novel birefringent α-BaB₂O₄ crystal［J］. Journal of Crystal Growth， 1998， 191（3）： 517-519.
[10]	APPEL R， DYER C D， LOCKWOOD J N. Design of a broadband UV-visible alpha-barium borate polarizer［J］. Applied Optics， 2002， 41（13）： 2470-2480. PMID
[11]	LIU J F， HE X M， XU J， et al. The study on properties of Sr²⁺-doped α-BBO crystal［J］. Journal of Crystal Growth， 2004， 260（3/4）： 486-489.
[12]	WU S F， WANG G F， XIE J L， et al. Growth of large birefringent α-BBO crystal［J］. Journal of Crystal Growth， 2002， 245（1/2）： 84-86.
[13]	CHEN X L， ZHANG F F， SHI Y J， et al. MBaYB₆O₁₂ （M = Rb， Cs）： two new rare-earth borates with large birefringence and short ultraviolet cutoff edges［J］. Dalton Transactions， 2018， 47（3）： 750-757.
[14]	JIA Z， ZHANG N N， MA Y Y， et al. Top-seeded solution growth and optical properties of deep-UV birefringent crystal Ba₂Ca（B₃O₆）₂ ［J］. Crystal Growth & Design， 2017， 17（2）： 558-562.
[15]	LV X S， WANG P， YU H J， et al. Growth and optical properties of a promising deep-ultraviolet birefringent crystal Ba₂Mg（BO₃）₂ ［J］. Optical Materials Express， 2019， 9（9）： 3835.
[16]	WANG X F， WANG Y， ZHANG B B， et al. CsB₄O₆F： a congruent-melting deep-ultraviolet nonlinear optical material by combining superior functional units［J］. Angewandte Chemie International Edition， 2017， 56（45）： 14119-14123.
[17]	ZHANG H， ZHANG M， PAN S L， et al. Na₃Ba₂（B₃O₆）₂F： next generation of deep-ultraviolet birefringent materials［J］. Crystal Growth & Design， 2015， 15（1）： 523-529.
[18]	陈幸龙. 新型紫外、深紫外双折射晶体和非线性光学晶体的探索、生长及性能研究［D］. 乌鲁木齐：中国科学院大学， 2018： 98-122.
	CHEN X L. Exploration， growth and properties of new ultraviolet， deep ultraviolet birefringence crystals and nonlinear optical crystals［D］. Urumqi ： University of Chinese Academy of Sciences， 2018： 98-122 （in Chinese）.
[19]	CHEN X L， ZHANG B B， ZHANG F F， et al. Designing an excellent deep-ultraviolet birefringent material for light polarization［J］. Journal of the American Chemical Society， 2018， 140（47）： 16311-16319. DOI PMID
[20]	FUJIMOTO Y， YANAGIDA T， KAWAGUCHI N， et al. Characterizations of Ce³⁺-doped CaB₂O₄ crystalline scintillator［J］. Crystal Growth & Design， 2012， 12（1）： 142-146.
[21]	FUJIMOTO Y， YANAGIDA T， KAWAGUCHI N， et al. Crystal growth and characterization of calcium metaborate scintillators［J］. Nuclear Instruments and Methods in Physics Research Section A： Accelerators， Spectrometers， Detectors and Associated Equipment， 2013， 703： 7-10.
[22]	SCHLICHTING H. Boundary-layer theory ［M］. New York： McGraw-Hill， 1979.
[23]	JONES S F， EVANS G M， GALVIN K P. Bubble nucleation from gas cavities： a review ［J］. Advances in Colloid and Interface Science， 1999， 80（1）： 27-50.
[24]	TILLER W， JACKSON K， RUTTER J， et al. The redistribution of solute atoms during the solidification of metals ［J］. Acta Metallurgica， 1953， 1（4）： 428-437.

Inclusion Defects in Ca（BO₂）₂ Crystals Grown by Czochralski Method

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