Combined Magnetic and Single-Crystal X-ray Structural Study of the Linear Chain Antiferromagnet [(CH3)4N][MnCl3] under Varying Pressure
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- 作者：Somchai Tancharakorn ; Francesca P. A. Fabbiani ; David R. Allan ; Konstantin V. Kamenev ; and Neil Robertson
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：July 19, 2006
- 年：2006
- 卷：128
- 期：28
- 页码：9205 - 9210
- 全文大小：128K
- 年卷期：v.128,no.28(July 19, 2006)
- ISSN：1520-5126
文摘
The magnetic susceptibility and single-crystal X-ray structure of the one-dimensional Heisenbergantiferromagnetic chain tetramethylammonium manganese trichloride (TMMC) have been studied underpressure as a facile route to develop structure-property relationships. The X-ray structure of TMMC wasdetermined at 0, 2.1, 3.8, 6.8, 12.2, and 17.0 kbar using diamond-anvil cell techniques and synchrotronradiation. The space group is confirmed to be P63/m up to 17 kbar, and structural refinement shows thatthe Mn-Mn separations between and along the chains change by about 3.4 and 2.5%, respectively, over17 kbar. A structural transition from hexagonal to monoclinic symmetry possibly occurs at 17 kbar, associatedwith a loss of crystal quality. Variable-temperature magnetic susceptibility data were taken at 0, 0.3, 1.5,2.9, 4.0, 5.2, and 6.5 kbar and show that the intrachain coupling constant changes from -6.85 to -7.81K over this range. The interchain coupling constant of -0.54 K can also be extracted from the Fishermodel modified for interacting chains. The pressure-temperature diagram shows the slope of the intrachainantiferromagnetic coupling with pressure, 
TIAF/P, changes from 0.5 to 1.6 K/kbar at 2 kbar where thestructure changes from P21/a to P21/m. Comparison of the magnetic and structural data are consistentwith the power-law relationship developed by Bloch where J 
r-n, r = Mn···Mn separation and n 
10.
TIAF/P, changes from 0.5 to 1.6 K/kbar at 2 kbar where thestructure changes from P21/a to P21/m. Comparison of the magnetic and structural data are consistentwith the power-law relationship developed by Bloch where J r-n, r = Mn···Mn separation and n 10.