TY - JOUR
T1 - 1H-NMR spin-lattice relaxation rate of the quantum spin system (CH 3) 2CHNH 3Cu(Cl xBr 1-x) 3 with x = 0 and 0.35
AU - Oosawa, Akira
AU - Suzuki, Takao
AU - Kanada, Keishi
AU - Kojima, Satoshi
AU - Goto, Takayuki
AU - Manaka, Hirotaka
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2009/5
Y1 - 2009/5
N2 - The spin-lattice relaxation rate T 1 -1 of 1H-NMR has been measured in (CH 3 ) 2CHNH 3Cu(Cl xBr l-x) 3 with x - 0 and 0.35, in order to investigate their microscopic magnetism. Previous macroscopic magnetization and specific heat measurements suggested that these two exist in a singlet-dimer phase. The temperature dependence of T 1 -1 in an x - 0 system decreased exponentially toward zero, providing microscopic evidence of a gapped singlet ground state, which is consistent with results of macroscopic experiments. At the same time, in the x = 0.35 system, T 1 -1 showed a sharp peak structure at approximately 7.5 K but no splitting of 1H-NMR spectra, indicative of magnetic ordering. We discuss the observed sharp peak structure in the x - 0.35 system with the soft mode toward the exotic magnetic ground state suggested by recent μSR experiments.
AB - The spin-lattice relaxation rate T 1 -1 of 1H-NMR has been measured in (CH 3 ) 2CHNH 3Cu(Cl xBr l-x) 3 with x - 0 and 0.35, in order to investigate their microscopic magnetism. Previous macroscopic magnetization and specific heat measurements suggested that these two exist in a singlet-dimer phase. The temperature dependence of T 1 -1 in an x - 0 system decreased exponentially toward zero, providing microscopic evidence of a gapped singlet ground state, which is consistent with results of macroscopic experiments. At the same time, in the x = 0.35 system, T 1 -1 showed a sharp peak structure at approximately 7.5 K but no splitting of 1H-NMR spectra, indicative of magnetic ordering. We discuss the observed sharp peak structure in the x - 0.35 system with the soft mode toward the exotic magnetic ground state suggested by recent μSR experiments.
KW - (CH ) CHNH Cu(Cl Br, )
KW - Bond randomness
KW - H-NMR
KW - Quantum spin system
KW - Spin gap
KW - Spin-lattice relaxation rate T
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U2 - 10.1143/JPSJ.78.053702
DO - 10.1143/JPSJ.78.053702
M3 - Article
AN - SCOPUS:67649127068
VL - 78
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 5
M1 - 053702
ER -