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本文合成出除Pm以外的全部稀土硝酸盐的二甲亚砜晶体,并生长出大尺寸的La和Nd的晶体(分别为60×28×25和80×28×28mm)。从La至Gd的组成为RE(NO_3)_3·4DMSO,从Tb至Lu(包括Y)的组成为为RE(NO_3)_3·3DMSO,由于镧系收缩引起的空间位阻,使结合的DMSO的数目从4减为3。测定了一些稀土的光谱和发光性质。比较Nd~(3+)在水溶液中和在DMSO中的吸收光谱,观察到在DMSO中Nd~(3+)的谱带向长波位移,表明了在DMSO中,RE—O键具有一定程度的共价性。当晶体在850℃的空气中进行热分解时,三价稀土的热分解产物的组成为RE_20_2SO_4。测定了全部稀土硝酸盐的二甲亚砜晶体的磁化率,它们随原子序的增大呈现具有双峰的周期性变化。
In this paper, dimethyl sulfoxide crystals of all rare earth nitrates except Pm were synthesized and large crystals of La and Nd (60 × 28 × 25 and 80 × 28 × 28mm, respectively) were grown. The composition of La to Gd is RE (NO 3) 3 · 4DMSO, the composition of Tb to Lu (including Y) is RE (NO 3) 3 · 3DMSO, the steric hindrance due to lanthanoid contraction causes the bound DMSO The number is reduced from 4 to 3. The spectra and luminescence properties of some rare earths were determined. By comparing the absorption spectra of Nd ~ (3+) in aqueous solution and in DMSO, the shift of the Nd ~ (3 +) band to long wavelength was observed in DMSO, indicating that the RE-O bond in DMSO has a certain degree of Covalent. When the crystals are thermally decomposed in the air at 850 ° C, the thermal decomposition product of the trivalent rare earth is composed of RE_20_2SO_4. The magnetic susceptibilities of dimethyl sulfoxide crystals of all rare earth nitrate salts were determined. They showed a bimodal periodicity with the increase of atomic number.