Search results for "Magnetism"

Spin polarization in electrodeposited thin films of the molecule-based magnetic semiconductor Cr5.5(CN)12·11.5H2O

2013

The magnetoresistance (MR) effect of thin films of the Prussian Blue Analogue (PBA) Cr5.5(CN)12·11.5H2O, prepared by electrochemical deposition, has been measured using the standard two-point probe method. This molecule-based ferrimagnetic material, with a Tc = 240 K, exhibits MR up to 2% at 6 T and 200 K.

Electron Transfer, Linkage Isomerization, Bulk Magnetic Order, and Spin-Glass Behavior in the Iron Hexacyanomanganate Prussian Blue Analogue

1999

Langmuir-Blodgett films based on Prussian Blue derivatives: Towards new hybrid magnetic materials

1999

Abstract The adsorption of dissolved Prussian Blue derivatives along a positively charged monolayer leads to new Langmuir-Blodgett (LB) films presenting a ferromagnetic state at low temperature. Such organic/inorganic systems containing inorganic sheets between organic amphiphilic layers constitute a new series of magnetic lamellar materials.

Photomagnetism of Molecular Systems

2001

This article reviews various classes of transition metal compounds which display in the solid state light sensitive electronic structure modifications accompanied by drastic changes of their magnetic and/or optical properties, i.e., photomagnetism. Selected examples from this rapidly expanding field, include spin crossover, stilbenoid and nitrosyl complexes, as well as Prussian blue analogues.

H(II) centers in natural silica under repeated UV laser irradiations

2004

We investigated the kinetics of H(II) centers (=Ge'-H) in natural silica under repeated 266nm UV irradiations performed by a Nd:YAG pulsed laser. UV photons temporarily destroy these paramagnetic defects, their reduction being complete within 250 pulses. After re-irradiation, H(II) centers grow again, and the observed recovery kinetics depends on the irradiation dose; multiple 2000 pulses re-irradiations induce the same post-irradiation kinetics of H(II) centers after each exposure cycle. The analysis of these effects allows us to achieve a deeper understanding of the dynamics of the centers during and after laser irradiation.

Geometrical control of pure spin current induced domain wall depinning.

2017

[EN] We investigate the pure spin-current assisted depinning of magnetic domain walls in half ring based Py/Al lateral spin valve structures. Our optimized geometry incorporating a patterned notch in the detector electrode, directly below the Al spin conduit, provides a tailored pinning potential for a transverse domain wall and allows for a precise control over the magnetization configuration and as a result the domain wall pinning. Due to the patterned notch, we are able to study the depinning field as a function of the applied external field for certain applied current densities and observe a clear asymmetry for the two opposite field directions. Micromagnetic simulations show that this …

Crystal engineering of 3-D coordination polymers by pillaring ferromagnetic copper(ii)-methylmalonate layers

2007

Three new copper(II) complexes of formula [Cu(Memal)(H2O)]n (1), [Cu2(pyz)(Memal)2] (2) and [Cu2(4,4′-bpy)(Memal)2(H2O)2] (3) (Memal = methylmalonate, pyz = pyrazine and 4,4′-bpy = 4,4′-bipyridine) were obtained and structurally characterized by X-ray diffraction. Complex 1 is a square grid of aquacopper(II) units which are linked by carboxylate-methylmalonate groups in the anti–syn (equatorial–equatorial) coordination mode. The crystal structures of 2 and 3 consist of corrugated layers of copper(II) (2) and aquacopper(II) (3) units with intralayer carboxylate-methylmalonate bridges in the anti–syn (equatorial–apical) coordination mode which are linked through pyrazine (2) and 4,4′-bipyridi…

Precise Control and Consecutive Modulation of Spin Transition Temperature Using Chemical Migration in Porous Coordination Polymers

2011

Precise control of spin transition temperature (T(c)) is one of the most important challenges in molecular magnetism. A Hofmann-type porous coordination polymer {Fe(pz)[Pt(II)(CN)(4)]} (1; pz = pyrazine) exhibited cooperative spin transition near room temperature (T(c)(up) = 304 K and T(c)(down) = 284 K) and its iodine adduct {Fe(pz)[Pt(II/IV)(CN)(4)(I)]} (1-I), prepared by oxidative addition of iodine to the open metal sites of Pt(II), raised the T(c) by 100 K. DSC and microscopic Raman spectra of a solid mixture of 1-I and 1 revealed that iodine migrated from 1-I to 1 through the grain boundary after heating above 398 K. We have succeeded in precisely controlling the iodine content of {Fe…

High-dimensional malonate-based materials: Synthesis, crystal structures and magnetic properties of [M2(mal)2(L)(H2O)2]n·n(H2O) M = Zn(ii), Co(ii); H…

2003

Four novel coordination polymers [M2(mal)2(pym)(H2O)]n·nH2O, M = Zn (1), Co (2) and [M2(mal)2(pyz)(H2O)]n·nH2O, M = Zn (3), Co (4) (H2mal = malonic acid, pym = pyrimidine, pyz = pyrazine), have been synthesized. Compounds 1 and 2 are isomorphous, as are compounds 3 and 4. X-ray diffraction experiments reveal that 1–4 exhibit an interesting 3D-network, containing malonate and either pyrimidine (1 and 2) and pyrazine (3 and 4) as organic ligands. Variable-temperature magnetic susceptibility measurements indicate the occurrence of weak antiferromagnetic interactions between Co(II) ions in 2 and 4.

Metamagnetism in hydrophobically induced carboxylate (phenylmalonate)-bridged copper(II) layers

2006

Self-assembly of copper(II) ions, phenylmalonate and pyrimidine yields the layered compound [Cu(pym)(Phmal)]n ( 1) where intralayer ferro- and interlayer antiferromagnetic interactions occur with three-dimensional antiferromagnetic ordering at Tc = 2.15 K Lloret Pastor, Francisco, Francisco.Lloret@uv.es ; Julve Olcina, Miguel, Miguel.Julve@uv.es