Structural phase transition in KHCO3
Structural phase transition in KHCO3
复制标题
KHCO3 中的结构相变
DOI：
10.1016/0022-4596(90)90133-i
复制
发表时间：
1990
影响因子：
3.3
通讯作者：
K. Yamamoto
中科院分区：
文献类型：
--
作者：
S. Kashida;K. Yamamoto
利用在相变点以下和以上收集的三维数据研究了KHCO 3的结构相变。在318 K以上，晶体结构从室温相（单斜空间群P2 1 a）变为高温相（单斜空间群C2 m），两者都含有四个分子式单元。晶胞参数为a= 15.195（1）Ω，B= 5.640（1）Ω，c= 3.734（1）Ω，β= 104.86（1）°，v= 309.28 A3（353 K）.通过全矩阵最小二乘法对结构进行细化，最终R因子为0.023。从傅立叶差谱图中氢原子的位置可以推断，该相变是由（HCO 3）2二聚体的有序-无序引起的。
The structural phase transition of KHCO 3 has been studied using three-dimensional data collected both below and above the transition point. Above 318 K, the crystal structure changes from the room temperature phase (monoclinic space group P2 1 a) to a high temperature phase (monoclinic space group C2 m), both containing four formula units. The cell dimensions are a= 15.195 (1) Å, b= 5.640 (1) Å, c= 3.734 (1) Å, and β= 104.86 (1)°, and v= 309.28 A 3 (at 353 K). The structure is refined by the full-matrix least-squares method and final R-factor is 0.023. From the hydrogen atoms revealed in the difference Fourier map, it is concluded that the phase transition is ascribed to the order-disorder of the (HCO 3) 2 dimer.