Per Nordblad

Near-Room-Temperature Colossal Magnetodielectricity and Multiglass Properties in Partially Disordered La2NiMnO6

We report magnetic, dielectric, and magnetodielectric responses of the pure monoclinic bulk phase of partially disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this compound is an intrinsically multiglass system with a large magnetodielectric coupling (8%-20%) over a wide range of temperatures (150-300 K). Specifically, our results establish a unique way to obtain colossal magnetodielectricity, independent of any striction effects, by engineering the asymmetric hopping contribution to the dielectric constant via the tuning of the relative-spin orientations between neighboring magnetic ions in a transition-metal oxide system. We discuss the role of antisite (Ni-Mn) disorder in emergence of these unusual properties.

Memory and Chaos Effects in Spin Glasses

New low frequency ac susceptibility measurements on two different spin glasses show that cooling/heating the sample at a constant rate yields an essentially reversible (but rate dependent)

Energy barrier distribution of a noninteracting nano-sized magnetic particle system

\ensuremath{\chi}(T)

Memory and superposition in a spin glass

curve; a downward relaxation of

Short-range ferromagnetism and spin-glass state in Y 0.7 Ca 0.3 MnO 3

\ensuremath{\chi}

Critical dynamics of an interacting magnetic nanoparticle system

occurs during a temporary stop at constant temperature (aging). Two main features of our results are (i) when cooling is resumed after such a stop,

Towards equilibrium in spin glasses (invited)

\ensuremath{\chi}

CHEMICAL VAPOR-DEPOSITION OF THE SUPERCONDUCTING YBA2CU3O7-X PHASE USING HALIDES AS METAL SOURCES

goes back to the reversible curve (chaos), and (ii) upon reheating,

Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of Mn

\ensuremath{\chi}

Nonequilibrium magnetic properties of single-crystalline La 0.7 Ca 0.3 CoO 3

perfectly traces the previous aging history (memory). We discuss implications of our results for a real space (as opposed to phase space) picture of spin glasses.