Abstract Calcium orthovanadate Ca3(VO4)2 crystals with the whitlockite structure as nominally pure as doped with manganese ions have been grown by the Czochralski method from melt in air in the [100] direction. The single crystals of optical-quality were obtained for 0.05–2 wt % Mn2O3 doping level in the melt. X-ray diffraction analysis was carried out. Analyze of the parameters of diffraction peaks indicates the microstructure improving for manganese doped crystals. The absorption spectrum of doped Ca3(VO4)2:Mn is characterized by a combination of absorption bands specific for Mn2+, Mn3+ and Mn5+ ions, it was also proved by spectroscopic measurements. Two fluorescence spectra were observed under 670 nm excitation: narrow fluorescence line peaking at about 1180 nm, which quite well fits the position of Mn5+ ions and broad band peaking at 1250 nm, which quite well fits the position of Mn3+ ions. Fluorescence in the visible range was not observed in Ca3(VO4)2:Mn crystal. The specific domain structure of ferroelectric Ca3(VO4)2 crystal was revealed by the method of selective chemical etching depending on crystal composition and thermal treatment. The anisotropic character of the optical properties of the material was estimated.

中文翻译：

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锰掺杂Ca3(VO4)2单晶的生长及性能

摘要 原钒酸钙 Ca3(VO4)2 晶体具有白铁矿结构，标称纯，掺杂了锰离子，已通过直拉法从空气中的熔体中沿 [100] 方向生长。在熔体中掺杂 0.05-2 wt% Mn2O3 时，获得了光学质量的单晶。进行X射线衍射分析。衍射峰参数分析表明，锰掺杂晶体的微观结构得到改善。掺杂 Ca3(VO4)2:Mn 的吸收光谱的特征是结合了 Mn2+、Mn3+ 和 Mn5+ 离子的特定吸收带，光谱测量也证明了这一点。在 670 nm 激发下观察到两种荧光光谱：窄荧光谱线在 1180 nm 左右达到峰值，与 Mn5+ 离子的位置非常吻合，宽带峰在 1250 nm 这非常适合 Mn3+ 离子的位置。在 Ca3(VO4)2:Mn 晶体中未观察到可见光范围内的荧光。铁电Ca3(VO4)2晶体的特定畴结构通过根据晶体成分和热处理的选择性化学蚀刻的方法来揭示。估计了材料光学特性的各向异性特征。