TY - JOUR
T1 - Observation of a transient magnetization plateau in a quantum antiferromagnet on the Kagomé lattice
AU - Narumi, Y.
AU - Katsumata, K.
AU - Honda, Z.
AU - Domenge, J. C.
AU - Sindzingre, P.
AU - Lhuillier, C.
AU - Shimaoka, Y.
AU - Kobayashi, T. C.
AU - Kindo, K.
PY - 2004/3
Y1 - 2004/3
N2 - The magnetization process of an S = 1/2 antiferromagnet on the Kagomé lattice, [Cu3(titmb)2(OCOCH 3)6] · H2O{titmb = 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6 trimethylbenzene}, has been measured at very low temperatures in both pulsed and steady fields. We have found a new dynamical behavior in the magnetization process. A plateau at one third of the saturation magnetization Ms appears in the pulsed-field experiments for intermediate sweep rates of the magnetic field and disappears in the steady-field experiments. A theoretical analysis using exact diagonalization yields J1 = -19 ± 2 K and J2 = 6 ± 2 K, for the nearest-neighbor and second-nearest-neighbor interactions, respectively. This set of exchange parameters explains the very low saturation field and the absence of the plateau in the thermodynamic equilibrium as well as the two-peak feature in the magnetic heat capacity observed by Honda et al (Z. Honda et al., J. Phys. Condens. Matter, 14 (2002) L625). Supported by numerical results we argue that a dynamical order by disorder phenomenon could explain the transient appearance of the Ms/3 plateau in pulsed-field experiments.
AB - The magnetization process of an S = 1/2 antiferromagnet on the Kagomé lattice, [Cu3(titmb)2(OCOCH 3)6] · H2O{titmb = 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6 trimethylbenzene}, has been measured at very low temperatures in both pulsed and steady fields. We have found a new dynamical behavior in the magnetization process. A plateau at one third of the saturation magnetization Ms appears in the pulsed-field experiments for intermediate sweep rates of the magnetic field and disappears in the steady-field experiments. A theoretical analysis using exact diagonalization yields J1 = -19 ± 2 K and J2 = 6 ± 2 K, for the nearest-neighbor and second-nearest-neighbor interactions, respectively. This set of exchange parameters explains the very low saturation field and the absence of the plateau in the thermodynamic equilibrium as well as the two-peak feature in the magnetic heat capacity observed by Honda et al (Z. Honda et al., J. Phys. Condens. Matter, 14 (2002) L625). Supported by numerical results we argue that a dynamical order by disorder phenomenon could explain the transient appearance of the Ms/3 plateau in pulsed-field experiments.
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U2 - 10.1209/epl/i2003-10164-5
DO - 10.1209/epl/i2003-10164-5
M3 - Article
AN - SCOPUS:2142642166
VL - 65
SP - 705
EP - 711
JO - Journal de Physique (Paris), Lettres
JF - Journal de Physique (Paris), Lettres
SN - 0295-5075
IS - 5
ER -