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Co-doped ZnO is the prototypical dilute magnetic oxide showing many of the characteristics of ferromagnetism. The microscopic origin of the long range order however remains elusive, since the conventional mechanisms for the magnetic…

Materials Science · Physics 2015-05-18 Thomas Archer , Chaitanya Das Pemmaraju , Stefano Sanvito

We report here enhancement of ferromagnetism in pure ZnO upon thermal annealing with the ferromagnetic transition temperature Tc above room temperature. We observe a finite coercive field upto 300K and a finite thermoremanent magnetization…

Materials Science · Physics 2007-09-25 S. Banerjee , M. Mandal , N. Gayathri , M. Sardar

We use the Kondo lattice model to investigate the possibility of ferromagnetism and half-metallicity in local moment systems. Using the spectral density approach and making use of the fact that the spontaneous magnetization of local moment…

Materials Science · Physics 2015-05-28 L. Haritha , G. Gangadhar Reddy , A. Ramakanth

Room temperature ferromagnetic hysteresis is observed in commercial SrTiO$_3$ substrates purchased from a variety of suppliers. It is shown that the ferromagnetic signal comes from the unpolished surfaces. Surface impurity phases cannot be…

Materials Science · Physics 2015-05-19 D. A. Crandles , B. DesRoches , F. S. Razavi

The effect of hydrogenation on magnetic properties of Zn0.85Co0.05Li0.10O nanoparticles is presented. It was found that the sample hydrided at room temperature (RT) showed weak ferromagnetism (FM) while that hydrided at 400oC showed robust…

Materials Science · Physics 2009-11-11 O. D. Jayakumar , I. K. Gopalakrishnan , K. Shasikala , S. K. Kulshreshtha

ZnO nanoparticles with Wurtzite structure were prepared by chemical methods at low temperature in aqueous solution. Nanoparticles are in the range from about 10 to 30 nm. Ferromagnetic properties were observed from 2 K to room temperature…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 R. Escudero , R. Escamilla

Structural and magnetic properties have been studied for polycrystalline Zn_1-xMn_xO (x=0.02, 0.03, 0.05). Low-temperature (~500 oC) synthesis leaves unreacted starting ZnO and manganese oxides. Contrary to a recent report, no bulk…

Materials Science · Physics 2016-08-31 S. Kolesnik , B. Dabrowski

Ab initio studies have theoretically predicted room temperature ferromagnetism in crystalline SnO2, ZrO2 and TiO2 doped with non magnetic element from the 1A column as K and Na. Our purpose is to address experimentally the possibility of…

Materials Science · Physics 2011-01-25 S. K. Srivastava , P. Lejay , B. Barbara , S. Pailhès , V. Madigou , G. Bouzerar

The spontaneous vacuum magnetization at finite temperature is investigated in SU(2) gluodynamics within a consistent effective potential approach including the one-loop and the correlation correction contributions. To evaluate the latter…

High Energy Physics - Phenomenology · Physics 2009-10-31 Vladimir Skalozub , Michael Bordag

The prospects of half-metallic ferromagnetism being induced by the incorporation of C atoms into alkaline-earth-metal-oxides are investigated by the first principle calculation. The origin of the ferromagnetism is discussed through the…

Materials Science · Physics 2008-01-16 Van An Dinh , Masayuki Toyoda , Kazunori Sato , Hiroshi Katayama-Yoshida

The realization of semiconductors that are ferromagnetic above room temperature will potentially lead to a new generation of spintronic devices with revolutionary electrical and optical properties. Transition temperatures in doped ZnO are…

Strongly Correlated Electrons · Physics 2009-11-11 XH Xu , AJ Behan , M Ziese , HJ Blythe , JR Neal , A Mokhtari , MR Ibrahim , AM Fox , GA Gehring

The origin of room temperature (RT) ferromagneticlike behavior in ZnO-based diluted magnetic semiconductors is still an unclear topic. The present work concentrates on the appearance of RT magnetic moments in just mixed ZnO/Co3O4 mixtures…

Room-temperature ferromagnetism has been induced within ZnO single crystals by implant-doping with Fe ions. For an implantation temperature of 620 K and an ion fluence of 4x10^16 cm^-2, very tiny Fe particles, formed inside the host matrix,…

We present direct evidence of above room temperature magneto-electricity in single-phase Li0.05Ti0.02Ni0.93O with above-ambient antiferromagnetic ordering. Temperature-hysteresis in warming/cooling heat-flow thermograms establishes a…

Materials Science · Physics 2015-09-15 Jitender Kumar , Pankaj K. Pandey , A. M. Awasthi

The adsorption of hydrogen on the polar Zn-ended ZnO(0001) surface has been investigated by density functional {\it ab-initio} calculations. An on top H(1x1) ordered overlayer with genuine H-Zn chemical bonds is shown to be energetically…

Materials Science · Physics 2015-05-13 N. Sanchez , S. Gallego , J. Cerdá , M. C. Muñoz

SrTiO3 plays a central role in oxide electronics. It is the substrate of choice for functional oxide heterostructures based on perovskite-structure thin-film stacks, and its surface or interface with a polar oxide such as LaAlO3 can become…

Materials Science · Physics 2016-10-12 J. M. D. Coey , M Venkatesan , P Stamenov

The structural and magnetic effects of non-magnetic vanadium (V) doping in helimagnetic SrFeO$_{3-\delta}$ (SFO) are investigated, focusing on up to 3% substitution at the Fe site. Structural analysis from X-ray diffraction (XRD) and Raman…

A neutron scattering investigation of the magnetoelectric coupling in PbFe_{1/2}Nb_{1/2}O_{3} (PFN) has been undertaken. Ferroelectric order occurs below 400 K, as evidenced by the softening with temperature and subsequent recovery of the…

Materials Science · Physics 2018-07-20 C. Stock , S. R. Dunsiger , R. A. Mole , X. Li , H. Luo

We show that room temperature resistivity of Ba0.5Sr1.5Zn2Fe12O22 single crystals increases by more than three orders of magnitude upon being subjected to optimized heat treatments. The increase in the resistivity allows the determination…

Materials Science · Physics 2010-01-11 Y S Chai , S H Chun , S Y Haam , Y S Oh , Ingyu Kim , Kee Hoon Kim

The present work reproduces the room temperature ferromagnetism by doping magnetic Mn atoms in diamagnetic ZnO. The ferromagnetic ordering is extended up to 640 K in mechanical milled Zn0.95Mn0.05O samples. The bulk and nanocrystalline…

Strongly Correlated Electrons · Physics 2009-03-11 R. N. Bhowmik , Asok Poddar , A. Saravanan