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Title: Observation of the Pressure Dependent Reversible Enhancement of Tc and Loss of the Anomalous Constricted Hysteresis for [Ru2(O2CMe)4]3[Cr(CN)6]

Abstract

The temperature and pressure dependencies of the magnetization, M(T,P), of cubic [Ru2(O2CMe)4]3[Cr(CN)6] reveals that Tc reversibly increases with increasing pressure up to 83 % to 59 K at 12.8 kbar (2.1 K kbar-1), and the pressure dependence of the hysteresis, M(H,P), shows that the anomalous constricted hysteresis observed at ambient pressure disappears at higher pressure (see figure).

Authors:
; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
959611
Report Number(s):
BNL-82597-2009-JA
TRN: US201016%%755
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advanced Materials; Journal Volume: 19
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; HYSTERESIS; MAGNETIZATION; PRESSURE DEPENDENCE; national synchrotron light source

Citation Formats

Shum,W., Her, J., Stephens, P., Lee, Y., and Miller, J. Observation of the Pressure Dependent Reversible Enhancement of Tc and Loss of the Anomalous Constricted Hysteresis for [Ru2(O2CMe)4]3[Cr(CN)6]. United States: N. p., 2007. Web. doi:10.1002/adma.200602751.
Shum,W., Her, J., Stephens, P., Lee, Y., & Miller, J. Observation of the Pressure Dependent Reversible Enhancement of Tc and Loss of the Anomalous Constricted Hysteresis for [Ru2(O2CMe)4]3[Cr(CN)6]. United States. doi:10.1002/adma.200602751.
Shum,W., Her, J., Stephens, P., Lee, Y., and Miller, J. Mon . "Observation of the Pressure Dependent Reversible Enhancement of Tc and Loss of the Anomalous Constricted Hysteresis for [Ru2(O2CMe)4]3[Cr(CN)6]". United States. doi:10.1002/adma.200602751.
@article{osti_959611,
title = {Observation of the Pressure Dependent Reversible Enhancement of Tc and Loss of the Anomalous Constricted Hysteresis for [Ru2(O2CMe)4]3[Cr(CN)6]},
author = {Shum,W. and Her, J. and Stephens, P. and Lee, Y. and Miller, J.},
abstractNote = {The temperature and pressure dependencies of the magnetization, M(T,P), of cubic [Ru2(O2CMe)4]3[Cr(CN)6] reveals that Tc reversibly increases with increasing pressure up to 83 % to 59 K at 12.8 kbar (2.1 K kbar-1), and the pressure dependence of the hysteresis, M(H,P), shows that the anomalous constricted hysteresis observed at ambient pressure disappears at higher pressure (see figure).},
doi = {10.1002/adma.200602751},
journal = {Advanced Materials},
number = ,
volume = 19,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Synchrotron-based infrared and Raman spectroscopies were brought together with diamond anvil cell techniques and an analysis of the magnetic properties to investigate the pressure-induced high low spin transition in [Ru2(O2CMe)4]3[Cr(CN)6]. The extended nature of the diruthenium wavefunction combined with coupling to chromium-related local lattice distortions changes the relative energies of the and orbitals and drives the high low spin transition on the mixed-valence diruthenium complex. This is a rare example of an externally controlled metamagnetic transition in which both spin-orbit and spin-lattice interactions contribute to the mechanism.
  • We present a muon-spin relaxation study of local magnetism in the molecule-based metamagnet [Ru2(O2CMe)4]3[Cr(CN)6]. We observe magnetic order with TN = 33 K, although above 25 K the sublattice spins become less rigid and a degree of static magnetic disorder is observed. The comparison of measurements in applied magnetic field with simulations allows us to understand the origin of the muon response across the metamagnetic transition and to map out the phase diagram of the material. Applied hydrostatic pressures of up to 6 kbar lead to an increase in the local magnetic field along with a complex change in themore » internal magnetic field distribution.« less
  • The low temperature hysteretic behavior between 40 mK and 4.8 K was obtained for [Ru2(O2CMe)4]3[Fe(CN)6]. The unusual constricted hysteretic behavior reported for isomorphous [Ru2(O2CMe)4]3[Cr(CN)6] was not observed. Instead, the [Ru2(O2CMe)4]3-[Fe(CN)6] exhibits a single hysteresis loop and a temperature dependence of the coercivity atypical for a ferrimagnetic ordering transition. The coercive field, constant below ~0.3 K (1.06 kOe), shows a rapid initial decrease below 1 K, to continue decreasing at a slower rate up to at least 4.8 K. In contrast to [Ru2(O2CMe)4]3[Cr(CN)6] which has antiferromagnetic coupling of the ferrimagnetic lattices, due to the reduced spin on the [FeIII(CN)6]3-, [Ru2(O2CMe)4]3[Fe(CN)6] ferromagneticmore » coupling of the ferrimagnetic lattices dominates for [Ru2(O2CMe)4]3[Fe(CN)6].« less
  • Reaction of [Ru{sub 2}(O{sub 2}CMe){sub 4}]Cl and K{sub 2}[Ni(CN){sub 4}] forms [Ru{sub 2}(O{sub 2}CMe){sub 4}]{sub 2}[Ni(CN){sub 4}] with the targeted layered structure possessing Ru-N{triple_bond}C-Ni linkages, albeit strained, with Ru-N{triple_bond}C and Ni-C{triple_bond}N angles in the range of 147-167{sup o}. The magnetic properties of [Ru{sub 2}(O{sub 2}CMe){sub 4}]{sub 2}[Ni(CN){sub 4}] can be fit to a zero-field splitting model with D/k{sub B} = 95 K (66 cm{sup -1}).