Related papers: Magnetic defects promote ferromagnetism in Zn1-xCo…
Using the spectroscopies based upon x-ray absorption, we have studied the structural and magnetic properties of Zn$_{1-x}$Co$_{x}$O films ($x$ = 0.1 and 0.25) produced by reactive magnetron sputtering. These films show ferromagnetism with a…
The magnetic properties of Zn$_{1-x}$Co$_x$O ($x=0.07$ and 0.10) thin films, which were homo-epitaxially grown on a ZnO(0001) substrates with varying relatively high oxygen pressure, have been investigated using x-ray magnetic circular…
The nature of the often reported room temperature ferromagnetism in transition metal doped oxides is still a matter of huge debate. Herein we report on room temperature ferromagnetism in high quality Co-doped ZnO (Zn1-xCoxO) bulk samples…
Following the theoretical predictions of ferromagnetism in Mn- and Co-doped ZnO, several workers reported ferromagnetism in thin films as well as in bulk samples of these materials. While some observe room-temperature ferromagnetism, others…
Room-temperature ferromagnetism is observed in (110) oriented ZnO films containing 5 at % of Sc, Ti, V, Fe, Co or Ni, but not Cr, Mn or Cu ions. There are large moments, 1.9 and 0.5 muB/atom for Co- and Ti-substituted oxides, respectively.…
We have studied the structural, magnetic and electronic properties of Co-implanted ZnO (0001) films grown on Al2O3 (1120) substrates for different implantation doses and over a wide temperature range. Strong room temperature ferromagnetism…
Magnetic 3d-ions doped into wide-gap oxides show signatures of room temperature ferromagnetism, although their concentration is two orders of magnitude smaller than that in conventional magnets. The prototype of these exceptional materials…
We have studied the influence of intrinsic and extrinsic defects in the magnetic and electrical transport properties of Co-doped ZnO thin films. X ray absorption measurements show that Co substitute Zn in the ZnO structure and it is in the…
Structural and magnetic properties have been studied for polycrystalline Zn_{1-x}TM_xO, where TM (transition metal ions) = Mn, Fe, and Co. No bulk ferromagnetism was observed for single-phase materials, contrary to the existing theories.…
We report on the structural and magnetic properties of a cobalt-implanted ZnO film grown on a sapphire substrate. X-ray diffraction and transmission electron microscopy reveal the presence of a (10-10)-oriented hexagonal Co phase in the…
The prediction of ferromagnetism at room temperature in Co-ZnO thin films has generated a large interest in the community due to the possible applications. However, the results are controversial, going from ferromagnetism to…
Point defects in Ga- and Al-doped ZnO thin films are studied by means of first principles electronic structure calculations. Candidate defects are identified to explain recently observed differences in electrical and spectroscopical…
The structural, optical and magnetic properties of the Zn1-xMnxO (0 < x < 0.05) thin films synthesized by sol-gel technique have been analyzed in the light of modification of the electronic structure and disorder developed in the samples…
Fe-doped ZnO nanocrystals are successfully synthesized and structurally characterized by using x-ray diffraction and transmission electron microscopy. Magnetization measurements on the same system reveal a ferromagnetic to paramagnetic…
Despite a considerable effort aiming at elucidating the nature of ferromagnetism in ZnO-based magnetic semiconductor, its origin still remains debatable. Although the observation of above room temperature ferromagnetism has been reported…
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…
Cobalt and silver co-doping has been undertaken in ZnO thin films grown by pulsed laser deposition in order to investigate the ferromagnetic properties in ZnO-based diluted magnetic materials and to understand the eventual relation between…
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…
We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78 $\mu_B$ per carbon. The theoretical…
In a rather contradictory situation regarding magnetic data on Co-doped ZnO, we have succeeded in fabricating high-quality single crystalline Zn1-xCoxO (x=0.003-0.07) thin films. This gives us the possibility, for the first time, to examine…