论文标题
稀有地点的光学浮动区晶体生长，$ r \ mathbf {_ {2}} $ si $ \ mathbf {_ {2}}} $ $ $ $ $ $ \ mathbf {_ {7}}
Optical floating zone crystal growth of rare-earth disilicates, $R\mathbf{_{2}}$Si$\mathbf{_{2}}$O$\mathbf{_{7}}$ ($R=$ Er, Ho, and Tm)
论文作者
论文摘要
在稀土二硅酸盐化合物中看到的大量结构阶段有望具有同样丰富的有趣磁性特性。我们通过稀有地破坏家庭成员的光浮动区方法报告晶体生长，$ r_ {2} $ si $ _ {2} $ o $ $ _ {7} $（带有$ r = $ r = $ er，ho，ho和tm）。通过系统的研究，我们优化了ER $ _ {2} $ si $ _ {2} $ o $ $ $ _ {7} $的增长条件。我们首次使用浮动区方法成长，ho $ _ {2} $ si $ _ {2} $ o $ $ $ _ {7} $和tm $ _ {2} $ si $ _ {2} $ _ {2} $ o $ o $ _ {7} $ complass $ _ {7} $ _ {7} $ _ {7} $ _ {7} $ _ {7} $ _ {2} $ _ {2} $ gomiolds。我们表明，在多晶和单晶样品的合成中遇到的困难是由于在$ r $ -Si-O Systems的温度组合相图中的不同稀土硅酸盐化合物的相似热稳定性范围。添加少量的SIO $ _ {2} $过量的量允许粉末样品中存在的杂质阶段量最小化。在生长的Boules上收集的粉末X射线衍射数据的相组成分析表明，它们是单相，除了DiSilate的情况下，该相位是由两个相组成的。所有生长均导致多晶卷，从中可以分离出相当大的单晶。报告了用于合成和晶体生长的最佳条件，以及单晶$ r_ {2} $ si $ _ {2} $ o $ $ $ _ {7} $材料。 Erbium和Thulium Diailicate化合物的特定热量测量结果证实了$ t _ {\ Mathrm {n}} = $ 1.8 k的抗铁磁相过渡，用于D型ER $ _ {2} $ _ {2} $ si $ si $ _ {2} tm $ _ {2} $ si $ _ {2} $ o $ _ {7} $，建议短距离磁相关的开始。 e-type ho $ _ {2} $ si $ _ {2} $ o $ $ $ $ _ {7} $的磁化敏感性数据显示出HO旋转的抗铁磁序以下$ T_ \ Mathrm {n} = $2.3K。
The wealth of structural phases seen in the rare-earth disilicate compounds promises an equally rich range of interesting magnetic properties. We report on the crystal growth by the optical floating zone method of members of the rare-earth disilicate family, $R_{2}$Si$_{2}$O$_{7}$ (with $R=$ Er, Ho, and Tm). Through a systematic study, we have optimised the growth conditions for Er$_{2}$Si$_{2}$O$_{7}$. We have grown, for the first time using the floating zone method, crystal boules of Ho$_{2}$Si$_{2}$O$_{7}$ and Tm$_{2}$Si$_{2}$O$_{7}$ compounds. We show that the difficulties encountered in the synthesis of polycrystalline and single crystal samples are due to the similar thermal stability ranges of different rare-earth silicate compounds in the temperature-composition phase diagrams of the $R$-Si-O systems. The addition of a small amount of SiO$_{2}$ excess allowed the amount of impurity phases present in the powder samples to be minimised. The phase composition analysis of the powder X-ray diffraction data collected on the as-grown boules revealed that they were of single phase, except in the case of thulium disilicate, which comprised of two phases. All growths resulted in multi-grain boules, from which sizable single crystals could be isolated. The optimum conditions used for the synthesis and crystal growth of polycrystalline and single crystal $R_{2}$Si$_{2}$O$_{7}$ materials are reported. Specific heat measurements of erbium and thulium disilicate compounds confirm an antiferromagnetic phase transition below $T_{\mathrm{N}}=$ 1.8 K for D-type Er$_{2}$Si$_{2}$O$_{7}$ and a Schottky anomaly centered around 3.5 K in C-type Tm$_{2}$Si$_{2}$O$_{7}$, suggesting the onset of short-range magnetic correlations. Magnetic susceptibility data of E-type Ho$_{2}$Si$_{2}$O$_{7}$ reveals an antiferromagnetic ordering of the Ho spins below $T_\mathrm{N}=$ 2.3 K.
