High-temperature ferromagnetism in dilute magnetic oxides

Temperature-dependent orbital-moment anisotropy in dilute magnetic oxides

High-temperature ferromagnetism in Ni2+-doped ZnO aggregates prepared from colloidal diluted magnetic semiconductor quantum dots.

Ferromagnetism with T(c)>350 K is observed in the diluted magnetic semiconductor Ni(2+):ZnO synthesized from solution. Whereas colloidal Ni(2+):ZnO nanocrystals are paramagnetic, their aggregation gives rise to robust ferromagnetism. The appearance of ferromagnetism is attributed to the increase in domain volumes and the generation of lattice defects upon aggregation. The unusual temperature de...

Dilute Annealed Magnetism and High Temperature Superconductivity

It has become increasingly appreciated that the strong antiferromagnetic coupling between in-plane Cu atoms in most of the high-temperature superconductors is not merely fortuitous [ 1-4 ]. However a coherent understanding of exactly how the magnetic interactions influence the observed superconductivity has been elusive. Here we focus on the prototype compound, La2_xSrxCuO 4 ( " 2 1 4 " ) . We ...

Itinerant ferromagnetism in a Fermi gas with contact interaction: Magnetic properties in a dilute Hubbard model

Chia-Chen Chang,1 Shiwei Zhang,1,2,3 and David M. Ceperley4 1Department of Physics, College of William and Mary, Williamsburg, VA 23187, USA 2Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China 3Department of Physics, Renmin University of China, Beijing 100872, China 4Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA (Received 7 Septem...

Ferromagnetism in dilute magnetic semiconductors through defect engineering: Li-doped ZnO.

We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby s...