The chalcopyrite CdGeP2 doped with Mn have been recently found to exhibit room-temperature ferromagnetism. Isovalent substitution of the Cd site is expected, however, to create antiferromagnetism, in analogy with the well-known CdTe:Mn (d5) case. However, chalcopyrite semiconductors exhibit low-energy intrinsic defects. We show theoretically how ferromagnetism results from the interaction of Mn...

The stability of the charge-stacked structure vis-à-vis the charge-alternate structure in the half-doped manganites is studied with a model that includes electronic kinetic energy, onsite and intersite Coulomb interactions, the Jahn–Teller energy, and the antiferromagnetic superexchange between the manganese core spins. It is shown that for a single zigzag chain, the electronic kinetic energy s...

Mn-doped GaAs thin films were grown at a high substrate temperature of 580 1C. During the growth process the Mn cell temperature was ramped at different rates, resulting in a variety of different Mn concentration depth profile slopes, as measured by dynamic secondary ion mass spectrometry (SIMS). Results show that controlling the Mn deposition rate via temperature during molecular beam epitaxy ...

Zn1 - x Mn x O nanoparticles have been synthesized by hydrothermal technique. The doping concentration of Mn can reach up to 9 at% without precipitation or secondary phase, confirmed by electron spin resonance (ESR) and synchrotron X-ray diffraction (XRD). Room-temperature ferromagnetism is observed in the as-prepared nanoparticles. However, the room-temperature ferromagnetism disappears after ...

The dc and ac conductivities of Mn-doped ZnO were investigated at temperatures from 10 to 100 K. The temperature dependence of the dc conductivity from 10 to 100 K shows an abrupt change at ;18 K, manifesting a much lower activation energy for conduction below 18 K. From 10 to 18 K, the ac conductivity, sac(v), varies as sac(v)5Av s in the frequency range from 10 to 10 Hz with s in the range of...

Luminescence data for 6 manganese doped langbeinites, Aj B2 + (S04)3 , are reported. They are consistent with octahedral symmetry of the impurity center (substitutional in B site), although for the host lattice the B site is known to show three-fold axial (distorted octahedral) symmetry only. In accordance with previous conclusions from EPR data the luminescence parameters indicate structural r...

The phase diagram of order parameters for pairing and phase coherence in hole-doped cuprates is discussed. By examining carefully some recent inelastic neutron scattering data obtained on hole-doped cuprates and heavy fermion compound UPd2Al3 in which the superconductivity is mediated by spin fluctuations, we conclude that the coherent gap in hole-doped cuprates has most likely the magnetic ori...

Mn doped ZnO nanocomposite thin film coated on glass by a simple spin-coating method was used to degrade an azo textile dye from aqueous environment. Mn doped ZnO nanocomposite thin film was characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photo-reduction activity of photocatalyst was evaluated using an azo textile dye as organic contaminant irradiat...

The local density of states of Mn-Mn pairs in GaAs is mapped with cross-sectional scanning tunneling microscopy and compared with theoretical calculations based on envelope-function and tight-binding models. These measurements and calculations show that the crosslike shape of the Mn-acceptor wave function in GaAs persists even at very short Mn-Mn spatial separations. The resilience of the Mn-ac...