Single crystals of SmAl₃(BO₃)₄ were synthesized by the group growth on seeds method. The crystal structure was solved using a single‐crystal experiment and the purity of the bulk material was proved by the Rietveld method. This borate crystallizes in the monoclinic C2/c space group with unit‐cell parameters a = 7.2386 (3), b = 9.3412 (5), c = 11.1013 (4) Å and β = 103.2240 (10)°. IR and Raman spectroscopic analyses confirmed the monoclinic structure of SmAl₃(BO₃)₄. Under 532.1 nm excitation, luminescence spectra exhibit bands assignable to the transitions from ⁴G_5/2 to ⁶H_5/2, ⁶H_7/2, ⁶H_9/2 and ⁶H_11/2. The similarity of the luminescence spectra of the trigonal and monoclinic polymorphs is explained by the minor role of Sm—O bond distortion and the primary role of rotational distortion of SmO₆ octahedra. The smaller covalency of the Sm—O bond in alumoborates is deduced in comparison with galloborates. Calorimetric measurements did not reveal high‐temperature structural phase transitions up to a temperature of 720 K.

中文翻译：

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单斜SmAl3（BO3）4：合成，结构和光谱性质。

SmAl ₃（BO ₃）_4的单晶是通过种子生长法合成的。使用单晶实验解决了晶体结构，并通过Rietveld方法证明了块状材料的纯度。该硼酸盐在单斜C 2 / c空间群中结晶，晶胞参数为a = 7.2386（3），b = 9.3412（5），c = 11.1013（4）Å和β= 103.2240（10）°。红外和拉曼光谱分析证实了SmAl ₃（BO ₃）₄的单斜结构。下532.1 nm激发，发光光谱显示出频带分配中的过渡从⁴ ģ _5/2至⁶ ħ _5/2，⁶ ħ _7/2，⁶ ħ _9/2和⁶ ħ _11/2。Sm-O键畸变的次要作用和SmO ₆八面体的旋转畸变的主要作用解释了三角形和单斜晶型的发光光谱的相似性。与镓硼酸盐相比，推导了铝硼酸盐中Sm-O键的较小共价键。量热法测量未发现高达720 K的高温结构相变。