Unusual evolution of the magnetism on oxygen in La1-?Sr?CoO3

We present X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) data of La1-χSrχCoO3, for χ= 0.10-0.30, at the O K edge and then compare the results to local density approximation (LDA) and generalized gradient approximatio

Exchange bias in a columnar nanocrystalline Ni80Fe20/CoO thin film

The effects of interfacial coupling at the boundary of ferromagnetic and antiferromagnetic components in a nanoscale columnar-structured thin film of Ni80Fe20/CoO have been examined. Field-cooling the film results in very different temperature dependences of the enhanced coercivity and exchange-bias shift of the hysteresis loop. The exchange-bias temperature dependence is well described by thermal fluctuations of the interfacial spins while the coercivity temperature dependence indicates that single-domain-like columns are being coherently rotated by the thermal fluctuations of the interface spins. Furthermore, only a portion of the spins in the antiferromagnetic layer seem to be associated with the spin coupling that results in exchange bias. X-ray magnetic resonant scattering measurements show clearly the presence of canted Co interfacial moments that provide a local field which enables exchange bias at a significantly higher temperature than the onset of an enhanced coercivity

Antiferromagnetic order in Co doped Fe5GeTe2 probed by resonant magnetic x ray scattering

The quasi two dimensional van der Waals magnet Fe5 amp; 8722; amp; 948;GeTe2 has emerged as a promising platform for electronic and spintronic functionalities at room temperature, owing to its large ferromagnetic ordering temperature TC amp; 8776; 315 K. Interestingly, by cobalt Co substitution of iron in F5GT, i.e., Fe1 amp; 8722;xCox 5 amp; 8722; amp; 948;GeTe2 Co F5GT , not only can its magnetic transition temperature be further enhanced, but the magnetic and structural ground states can also be tuned. Specifically, an antiferromagnetic AFM order is induced beyond the Co doping level x amp; 8805;0.4. Here, we investigate the magnetic properties of a Co F5GT single crystal at x 0.45 1 , by utilizing the element specific, resonant magnetic x ray scattering technique. Our study reveals an A type, Ising like AFM ground state, with a transition temperature TN amp; 8776; 340 K. In addition, our work unveils an important contribution from Co magnetic moments to the magnetic order. The application of the in plane magnetic fields gradually polarizes the spin moments along the field direction, but without inducing incommensurate spin texture

Facile synthesis of Cu and Cu@Cu-Ni nanocubes and nanowires in hydrophobic solution in the presence of nickel and chloride ions

In this work, we report an example of the facile synthesis of methyl methacrylate/tert-butyl acrylate (MMA/tBA) gradient copolymers (poly(MMA-grad-tBA) using the Cu(0) and conventional ATRP ligands as catalysts in DMF solvent at 25 degrees C. Semi-batch copper(0)-mediated living radical copolymerization technique (Cu(0)-mediated LRP) was used for achieving the chain gradient microstructure of the resulting copolymers. We also compared copolymerizations with two different ATRP ligands at ambient temperature allowing control over the molecular weight and polydispersity with a quarter of catalyst concentration versus a conventional ATRP in dipolar protic solvent (i.e. DMF), while the reaction temperature up to 80 degrees C in a non-polar medium (i.e. toluene) in order to reach the above polymerization efficiency. The addition of a small amount of reducing agent (i.e. hydrazine hydrate) into the reaction system allows the reaction proceeding in the oxygen tolerant system without losing control and decreasing total conversion such as using the reagents without deoxygenating