Search for dissertations about: "antiferromagnetism"

Showing result 1 - 5 of 9 swedish dissertations containing the word antiferromagnetism.

  2. 1. Chemical Tuning of the Magnetic Interactions in Layer Structures

    Author : Sabina Ronneteg; Rolf Berger; J. Paul Attfield; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; neutron powder diffraction; magnetometry; layered magnetic structure; incommensurate helical structure; ThCr2Si2 type structure; antiferromagnetism; ferromagnetism; electronic structure calculations; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

    Abstract : Thin metal films have found their use in many magnetic devices. They form pseudo two-dimensional systems, where the mechanisms for the magnetic interactions between the layers are not completely understood. READ MORE

  4. 2. Synthesis, Nuclear Structure, and Magnetic Properties of some Perovskite Oxides

    Author : Mehreteab Tseggai; Per Nordblad; Roland Tellgren; Torbjörn Gustafsson; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Magnetic Perovskites; Neutron powder diffraction; SQUID; Synthesis; Nuclear structure; Antiferromagnetism; Ferromagnetism; Superexchange; Double exchange; Colossal magnetoresistance; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Abstract : Synthesis, nuclear structure, and magnetic properties of the perovskites: Nd0.7-xMgxSr0.3MnO3 (x=0.0, 0. READ MORE

  5. 3. Two-dimensional antiferromagnetism : from Schwinger bosons to spin waves

    Author : Ann Mattsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; honeycomb lattice; antiferromagnet; Heisenberg model;

    Abstract : .... READ MORE

  6. 4. Neutron spectroscopy studies of vibrational and diffusional dynamics in organometal halide and oxyhydride perovskites

    Author : Rasmus Lavén; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Metal halide perovskites; perovskites; phonons; quasielastic neutron scattering; inelastic neutron scattering; oxyhydrides; hydrogen dynamics.; diffusion;

    Abstract : This thesis deals with inelastic and quasielastic neutron scattering studies on the dynamical properties of the organometal halide perovskite system MA1-xFAxPbI3 (MA = methylammonium; FA = formamidinium) and of the layered perovskite-type oxyhydride SrVO2H. These materials systems are of high interest for their excellent photovoltaic performance (MA1-xFAxPbI3) and hydride-ion conductivity (SrVO2H) and concomitant promise for various technological devices; however, the local structure and dynamics underpinning these materials properties remain unclear. READ MORE

  7. 5. Phase transitions in high-temperature superconductors

    Author : Jack Lidmar; KTH; []
    Keywords : Superconductivity; Vortices; Phase transitions; Strongly correlated fermions; High-temperature superconductivity; Monte Carlo simulations.; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : Thermal fluctuations and disorder strongly influence the behaviour of hightemperature superconductors. In particular the vortices play a key role in determining their properties. In this thesis the main focus lies on phase transitions, both in ultra-thin films and in three-dimensional systems, which are driven by vortex fluctuations. READ MORE