Thermodynamic and Physical Properties of (NH4)2MnCl4∙2H2O by Nuclear Magnetic Resonance Relaxation Times
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The phase transition temperatures and thermodynamic properties of (NH4)2MnCl4∙2H2O grown by the slow evaporation method were studied using differential scanning calorimetry and thermogravimetric analysis. A structural phase transition occurred at temperature TC1 (=264 K), whereas the changes at TC2 (=460 K) and TC3 (=475 K) seemed to be chemical changes caused by thermal decomposition. In addition, the chemical shift and the spin-lattice relaxation time T1ρ were investigated using 1H magic-angle spinning nuclear magnetic resonance (MAS NMR), in order to understand the role of NH4+ and H2O. The rise in T1ρ with temperature was related to variations in the symmetry of the surrounding H2O and NH4+.
Abstract
The phase transition temperatures and thermodynamic properties of (NH4)2MnCl4∙2H2O grown by the slow evaporation method were studied using differential scanning calorimetry and thermogravimetric analysis. A structural phase transition occurred at temperature TC1 (=264 K), whereas the changes at TC2 (=460 K) and TC3 (=475 K) seemed to be chemical changes caused by thermal decomposition. In addition, the chemical shift and the spin-lattice relaxation time T1ρ were investigated using 1H magic-angle spinning nuclear magnetic resonance (MAS NMR), in order to understand the role of NH4+ and H2O. The rise in T1ρ with temperature was related to variations in the symmetry of the surrounding H2O and NH4+.
참고문헌 (16)
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