Single-Crystal Growth and Structure Determination of a New Oxide Apatite, NaLa9(GeO4)6O2
Single-Crystal Growth and Structure Determination of a New Oxide Apatite, NaLa9(GeO4)6O2
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DOI：
10.1006/jssc.1998.7845
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发表时间：
1998-09
影响因子：
5.4
通讯作者：
Masaru Takahashi;K. Uematsu;Z. Ye;Mineo Sato
中科院分区：
文献类型：
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作者：
Masaru Takahashi;K. Uematsu;Z. Ye;Mineo Sato
NaLa 9 Ge 6 O26，六方晶系，a =0.9883（2）nm，c =0.7267（3）nm，V =6.147（3）× 105 nm 3，空间群P63/ m，Z =1，D计算值= 5.739gcm-3，λ（Mo Kα）= 0.071069nm，μ = 225.16cm-1，对于966个测量的独特反射，F（000）=924，T =298 K，R =0.031，RW =0.037。用高温助熔剂法和熔体法生长了NaLa 9 Ge 6 O26单晶。晶体结构与硅酸盐氧磷灰石NaY 9 Si 6 O26相似. 4f阳离子位被La和Na无序占据。另一方面，6 h阳离子位点仅被La占据。该化合物构成氧磷灰石型结构家族的新成员，通式为A x Ln 10− x B 6 O 24 O 3− x（x =1，A =碱金属，B =Si、Ge，Ln =稀土）。
Abstract NaLa 9 Ge 6 O 26 , hexagonal, a =0.9883(2) nm, c =0.7267(3) nm, V =6.147(3)×10 5 nm 3 , space group P 6 3 / m , Z =1, D calc = 5.739 g cm −3 , λ (Mo Kα )=0.071069 nm, μ =225.16 cm −1 , F (000)=924, T =298 K, R =0.031, R w =0.037 for 966 measured unique reflections. Single crystals of NaLa 9 Ge 6 O 26 were grown both by a high-temperature flux method and from a melt system. The crystal structure was found to be similar to that of the silicate oxyapatite NaY 9 Si 6 O 26 . The 4 f cation sites are occupied disorderedly by La and Na. On the other hand, the 6 h cation sites are occupied by La only. This compound constitutes a new member of the oxyapatite-type structure family with general formula A x Ln 10− x B 6 O 24 O 3− x ( x =1, A =alkali metals, B =Si, Ge, Ln =rare earth).