Search results for "magnetism."

Titelbild: Cyanide-Bridged Iron(III)–Cobalt(II) Double Zigzag Ferromagnetic Chains: Two New Molecular Magnetic Nanowires (Angew. Chem. 13/2003)

2003

Syntheses, crystal structures and magnetic properties of polynuclear 1,4,5,8,9,12-hexaazatriphenylene (hat)-bridged copper(II) complexes

2001

Three polynuclear compounds containing copper(II) and 1,4,5,8,9,12-hexaazatriphenylene (hat) as the basic building blocks have been prepared, [Cu4(hat)2Cl8]n·6nH2O 1, [Cu(hat)(H2O)2]n[NO3]2n2, and [Cu2(hat)(H2O)6]n[SO4]2n·2nH2O 3, their crystal structures determined and variable-temperature magnetic susceptibility data measured. The basic building block in 1 is the dinuclear [Cu2(hat)Cl4] entity, two such units being connected to tetranuclear units through relatively strong axial Cu–Cl bonds (out-of-plane di-μ-chloro bridges). Weaker axial Cu⋯Cl interactions link the units into a sheet structure. In 2 and 3 hat-bridged copper(II) chains extending along glide planes are present. hat serves a…

A Covalently Cross-linked Polyetheretherketone Proton Exchange Membrane for DMFC

2009

The proton exchange membrane was prepared by covalent cross-linking sulfonated-sulfinated polyetheretherketone. The cross-linked membrane showed high proton conductivity (0.04 S/cm) with suitable water uptake, low methanol permeability (2.21 × 10-7 cm2/s) and good electrochemical stability. The results suggested that cross-linked polyetheretherketone membrane is particularly promising to be used as proton exchange membrane for the direct methanol fuel cell application.

Magnetization Relaxation in a Three‐Dimensional Ligated Cobalt Phosphonate Containing Ferrimagnetic Chains

2010

Magneto-Transport Results in Alq3 Based OSVs

2015

The achievement of good magnetoresistance signal at room temperature is an important requirement for the possible future development of organic devices for applications. However, until now only few works reported room temperature MR effect in organic spin valves (OSVs). In this regard, this chapter is dedicated to the investigation of Alq3-based OSVs where Alq3 molecule was chosen since it is a standard material in the field. A systematic study on Co/Alq3/Co OSVs will be presented showing room temperature MR results. Moreover, inelastic electron tunneling spectroscopy (IETS) technique will be used to prove spin injection into the organic layer. Finally, an insulating oxide barrier (Al2O3 or…

Magnetic moment investigations of epitaxial magnetite thin films

2008

In this report, we provide an x-ray magnetic circular dichroism (XMCD) study for 100nm thick epitaxial magnetite (Fe3O4) films on MgO (001) and Al2O3 (0001) substrates. For XMCD, we recorded the surface sensitive total electron yield and the bulk sensitive transmission spectra. From the analysis of the XMCD data, we find an increased Fe spin moment (10% larger) at the surface of the film on MgO (100) with respect to the corresponding bulk value of the film. Surface and bulk spin moments of the film on Al2O3(0001) are almost equal. For both films, the bulk orbital to spin moments ratio increases from zero at 70K to 0.03–0.04 at 300K. For Fe3O4∕MgO (001), the surface orbital to spin moment ra…

Electronics and Electromagnetism

2007

Role of P‐glycoprotein‐mediated secretion in absorptive drug permeabiity: An approach using passive membrane permeability and affinity to P‐glycoprot…

1999

Abstract It has been shown in vivo and in vitro that P‐glycoprotein (P‐gp) may be able to influence the permeability of its substrates across biological membranes. However, the quantitative contribution of the secretion process mediated by P‐gp on the overall permeability of membranes has not been determined yet. In particular, observations need to be clarified in which substrates showing high affinity to P‐glycoprotein, e.g., verapamil, apparently do not seem to be greatly influenced by P‐gp in their permeability and consequently also with respect to their extent of GI‐absorption after oral administration, whereas weaker substrates of P‐gp, e.g., talinolol, have clearly shown P‐gp‐related …

Oxalate-based 2D magnets: the series [NBu4][MIIMnIII(ox)3] (MII= Fe, Co, Ni, Zn; ox = oxalate dianion)

2006

The synthesis, structure and physical properties of the bimetallic oxalate-based molecular magnets containing MnIII of formula [NBu4][MIIMn(ox)3] (MII = Fe, Co, Ni, Zn; ox = oxalate dianion) are presented here. All compounds are isostructural, containing two-dimensional honeycomb bimetallic networks formed by alternating MII and MIII ions connected by oxalate anions. These compounds exhibit antiferromagnetic interactions that give rise to ferrimagnets or weak ferromagnets ordering at critical temperatures up to 21 K.

Polyoxometalate-Based Molecular Materials.

1998

Molecule-based materials with active physical properties, in particular electrical, magnetic, and optical, are a focus of contemporary materials chemistry research. Certainly, one reason for this interest has been the realization that these materials can exhibit cooperative properties typically associated with the inorganic network solids, as for example metallic conduction or even superconductivity,1 ferromagnetism,2 and nonlinear optical properties.3 With respect to the electrical properties, many important achievements were obtained in the 1970s with the discovery of the first molecule-based metal in 1972,4 namely the π-electron donor-acceptor complex [TTF][TCNQ] (TTF ) tetrathiafulvalen…