Procissi, D. and Arosio, P. and Orsini, F. and Marinone, M. and Cornia, A. and Lascialfari, A. (2009) Muon spin relaxation investigation of tetranuclear iron(III) Fe_4(OCH_3)_6(dpm)_6 molecular cluster. Physical Review B, 80 (9). 094421. ISSN 1098-0121 http://resolver.caltech.edu/CaltechAUTHORS:20091022-094602971
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We present a study of the spin dynamics of Fe_4(OCH_3)_6(dpm)_6 single molecule magnet by means of SQUID magnetization and muon relaxation (µ^(+)SR) measurements. In longitudinal field µ^+SR experiments performed at magnetic fields H=200, 1000 Oe, the muon asymmetry P(t) could be fitted by means of three components, the first constant, the second fast relaxing through a quasiexponential decay, and the third, the slowest relaxing, showing an exponential decay. The slowest muon relaxation rate studied as a function of temperature T displayed two structures, a broad peak at T~15/20 K and a shoulder at T<5 K, both decreasing in amplitude and displacing toward higher temperatures as the field is increased. To mimic qualitatively the temperature behavior λ(T) at the investigated fields, we used a function expressed as the sum of two Bloembergen-Purcell-Pound (BPP)-like laws, reproducing the mechanism of relaxation. The exponential data resulted well fitted by means of a heuristic model which takes into account two correlation times τ' and τ, related to the ground-state multiplet barrier (Δ'/k_B=7.25 K) and to the intermultiplet separation (Δ'/k_B=86.4 K) between S=5 and S=4.
|Additional Information:||© 2009 American Physical Society. Received 3 April 2009; revised 25 June 2009; published 29 September 2009. Magmanet Network of Excellence and QuEMolNa Research Training Network are gratefully acknowledged. P. Carretta and E. Micotti are thanked for help in experimental measurements and S. P. J. Cottrell for technical assistance.|
|Subject Keywords:||ground states; high-temperature effects; iron compounds; magnetisation; molecular clusters; molecular magnetism; muon probes; spin dynamics|
|Classification Code:||PACS number(s): 76.75.+i, 76.60.-k, 75.45.+j|
|Official Citation:||Muon spin relaxation investigation of tetranuclear iron(III) Fe[sub 4](OCH[sub 3])[sub 6](dpm)[sub 6] molecular cluster D. Procissi, P. Arosio, F. Orsini, M. Marinone, A. Cornia, and A. Lascialfari, Phys. Rev. B 80, 094421 (2009), DOI:10.1103/PhysRevB.80.094421|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||23 Oct 2009 16:47|
|Last Modified:||26 Dec 2012 11:29|
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