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...

Atomic and continuum effects in L10 magnets are investigated. Emphasis is on the competition between ferromagnetism, antiferromagnetism, and noncollinear order in both perfect and imperfect structures, and on the temperature dependence of the magnetic anisotropy. The applicability of micromagnetic and atomistic approaches depends on the length scales involved, but there is a broad range of phen...

We review the current understanding of superconductivity in the quasi-onedimensional organic conductors of the Bechgaard and Fabre salt families. We discuss the interplay between superconductivity, antiferromagnetism, and charge-density-wave fluctuations. The connection to recent experimental observations supporting unconventional pairing and the possibility of a tripletspin order parameter for...

A theory is proposed to describe the competition among antiferromagnetism (AF), spin glass (SG) and Kondo effect. The model describes two Kondo sublattices with an intrasite Kondo interaction strength JK and a random Gaussian interlattice interaction in the presence of a transverse field Γ. The Γ field is introduced as a quantum mechanism to produce spin flipping and the random coupling has ave...