Magnetic relaxations in a Tb-based single molecule magnet studied by quasielastic neutron scattering

Maiko Kofu; Takashi Kajiwara; Jason S. Gardner; Giovanna G. Simeoni; Madhusudan Tyagi; Antonio Faraone; Kenji Nakajima; Seiko Ohira-Kawamura; Motohiro Nakano; Osamu Yamamuro

doi:10.1016/j.chemphys.2013.10.004

Magnetic relaxations in a Tb-based single molecule magnet studied by quasielastic neutron scattering

Maiko Kofu
, Takashi Kajiwara
, Jason S. Gardner
, Giovanna G. Simeoni
, Madhusudan Tyagi
, Antonio Faraone
, Kenji Nakajima
, Seiko Ohira-Kawamura
, Motohiro Nakano
, Osamu Yamamuro

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

By using ac magnetic susceptibility and quasielatic neutron scattering (QENS) techniques, we have investigated a magnetization relaxation phenomenon of a rare-earth based single molecule magnet, TbCuC₁₉H ₂₀N₃O₁₆. We clearly identified and characterized two magnetic relaxations. The slower relaxation observed in the ac susceptibility is at the ms timescale around T=2 K and its activation energy is 16 K. On the other hand, the faster relaxation in the QENS measurements occurs on the timescale between ns and ps with activation energy of 174 K. The slower relaxation may occur through thermally activated tunneling among magnetic substates. We discuss two possible origins for the faster relaxation; one is a thermally activated tunneling between the higher excited states, the other is the magnetic relaxation coupled with the motion of ligands around the magnetic ions. This is the first clear observation of magnetic relaxation on the single molecule magnet revealed by QENS.

Original language	English
Pages (from-to)	147-152
Number of pages	6
Journal	Chemical Physics
Volume	427
DOIs	https://doi.org/10.1016/j.chemphys.2013.10.004
State	Published - Dec 12 2013
Externally published	Yes

Funding

We thank Dr. R. Paul (NCNR) for experimental supports on Prompt- experiments and Prof. T. Yamamura (Tohoku University) for kind supports of the magnetic experiments. This work is financially supported by the Grant-in-Aid for Exploratory Research No. 24655127, JSPS, Japan. The NSE experiment at NCNR was financially supported by Institute for Solid State Physics, the University of Tokyo, through the Travel Expense Support for Overseas program. This work utilized facilities supported in part by the National Science Foundation under Agreement No. DMR-0944772. The experiment in the MLF at J-PARC was performed with the approval of J-PARC (proposal No. 2010A0044).

Keywords

Ac susceptibility
Magnetic relaxation
Quasielastic neutron scattering
Single molecule magnet

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10.1016/j.chemphys.2013.10.004

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@article{398996efb34d4f7dba9d6d20bbbf0680,

title = "Magnetic relaxations in a Tb-based single molecule magnet studied by quasielastic neutron scattering",

abstract = "By using ac magnetic susceptibility and quasielatic neutron scattering (QENS) techniques, we have investigated a magnetization relaxation phenomenon of a rare-earth based single molecule magnet, TbCuC19H 20N3O16. We clearly identified and characterized two magnetic relaxations. The slower relaxation observed in the ac susceptibility is at the ms timescale around T=2 K and its activation energy is 16 K. On the other hand, the faster relaxation in the QENS measurements occurs on the timescale between ns and ps with activation energy of 174 K. The slower relaxation may occur through thermally activated tunneling among magnetic substates. We discuss two possible origins for the faster relaxation; one is a thermally activated tunneling between the higher excited states, the other is the magnetic relaxation coupled with the motion of ligands around the magnetic ions. This is the first clear observation of magnetic relaxation on the single molecule magnet revealed by QENS.",

keywords = "Ac susceptibility, Magnetic relaxation, Quasielastic neutron scattering, Single molecule magnet",

author = "Maiko Kofu and Takashi Kajiwara and Gardner, \{Jason S.\} and Simeoni, \{Giovanna G.\} and Madhusudan Tyagi and Antonio Faraone and Kenji Nakajima and Seiko Ohira-Kawamura and Motohiro Nakano and Osamu Yamamuro",

year = "2013",

month = dec,

day = "12",

doi = "10.1016/j.chemphys.2013.10.004",

language = "English",

volume = "427",

pages = "147--152",

journal = "Chemical Physics",

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TY - JOUR

T1 - Magnetic relaxations in a Tb-based single molecule magnet studied by quasielastic neutron scattering

AU - Kofu, Maiko

AU - Kajiwara, Takashi

AU - Gardner, Jason S.

AU - Simeoni, Giovanna G.

AU - Tyagi, Madhusudan

AU - Faraone, Antonio

AU - Nakajima, Kenji

AU - Ohira-Kawamura, Seiko

AU - Nakano, Motohiro

AU - Yamamuro, Osamu

PY - 2013/12/12

Y1 - 2013/12/12

N2 - By using ac magnetic susceptibility and quasielatic neutron scattering (QENS) techniques, we have investigated a magnetization relaxation phenomenon of a rare-earth based single molecule magnet, TbCuC19H 20N3O16. We clearly identified and characterized two magnetic relaxations. The slower relaxation observed in the ac susceptibility is at the ms timescale around T=2 K and its activation energy is 16 K. On the other hand, the faster relaxation in the QENS measurements occurs on the timescale between ns and ps with activation energy of 174 K. The slower relaxation may occur through thermally activated tunneling among magnetic substates. We discuss two possible origins for the faster relaxation; one is a thermally activated tunneling between the higher excited states, the other is the magnetic relaxation coupled with the motion of ligands around the magnetic ions. This is the first clear observation of magnetic relaxation on the single molecule magnet revealed by QENS.

AB - By using ac magnetic susceptibility and quasielatic neutron scattering (QENS) techniques, we have investigated a magnetization relaxation phenomenon of a rare-earth based single molecule magnet, TbCuC19H 20N3O16. We clearly identified and characterized two magnetic relaxations. The slower relaxation observed in the ac susceptibility is at the ms timescale around T=2 K and its activation energy is 16 K. On the other hand, the faster relaxation in the QENS measurements occurs on the timescale between ns and ps with activation energy of 174 K. The slower relaxation may occur through thermally activated tunneling among magnetic substates. We discuss two possible origins for the faster relaxation; one is a thermally activated tunneling between the higher excited states, the other is the magnetic relaxation coupled with the motion of ligands around the magnetic ions. This is the first clear observation of magnetic relaxation on the single molecule magnet revealed by QENS.

KW - Ac susceptibility

KW - Magnetic relaxation

KW - Quasielastic neutron scattering

KW - Single molecule magnet

UR - https://www.scopus.com/pages/publications/84890126286

U2 - 10.1016/j.chemphys.2013.10.004

DO - 10.1016/j.chemphys.2013.10.004

M3 - Article

AN - SCOPUS:84890126286

SN - 0301-0104

VL - 427

SP - 147

EP - 152

JO - Chemical Physics

JF - Chemical Physics

ER -

Magnetic relaxations in a Tb-based single molecule magnet studied by quasielastic neutron scattering

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Keywords

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