Ms
Ursula Bengaard Hansen
(The Niels Bohr Institute)
CoCl2·2D2O can be considered as an example of a one-dimensional magnetic system. The dominant magnetic interactions are ferromagnetic and couple nearest neighbour spins lying on chains oriented along the crystallographic c-axis. Weaker inter-chain interactions gives rise to an antiferromagnetic ordering below 17.2 K. When a magnetic field is applied along the easy axis CoCl2·2D2O has two...
Prof.
Carlo Maria Canali
(Linnaeus University)
Molecular quantum spintronics is an emerging field in condensed matter physics and nanoscience that combines concepts of spintronics and molecular electronics.
The present talk deals with theoretical investigations of molecular quantum spintronics with magnetic molecules, based on density functional theory (DFT). These molecules consist of a core of a few transition-metal (TM) atoms carrying...
Prof.
Carlo Maria Canali
(Linnaeus University)
Molecular quantum spintronics is an emerging field in condensed matter physics and nanoscience that combines concepts of spintronics and molecular electronics.
The present talk deals with theoretical investigations of molecular quantum spintronics with magnetic molecules, based on density functional theory (DFT). These molecules consist of a core of a few transition-metal (TM) atoms carrying...
Prof.
Kim Lefmann
(University of Copenhagen)
Neutron scattering experiments of the model system Cu(DCOO)$_2$·4D$_2$O (CFTD) have shown that
the energy and intensity spectra are suppressed at the wave-vector $q_M = (π, 0)$ when compared to
semi-classical linear spin wave theory. Finite temperature quantum Monte Carlo (QMC) methods
can reproduce the measured experimental spectra. Other methods such as Gutzwiller...
Mr
Christopher Røhl Andersen
(Niels Bohr Institute (Copenhagen))
Multiferroic compounds with the coexistence of magnetic and ferroelectric orders are well known from transition metal oxides with perovskite crystal structures. Recently, a new family of multiferroic oxides with other crystal structures has been found: *M*$_3$TeO$_6$ (*M* = Co, Mn, Ni).
Co$_3$TeO$_6$ has shown a complex magnetic ordering with several positions for the magnetic cations....
Prof.
Jon Goff
(Royal Holloway University of London)
In classical spin ice emergent magnetic monopole excitations have been predicted, and in quantum spin ice a Higgs transition is expected from a magnetic Coulomb liquid to a ferromagnetic phase. In this talk I shall explore how diffuse neutron scattering has been used to determine defect structures, the magnetic ground states and the monopole dynamics in pyrochlores. Polarised neutrons are used...
Mr
Hailiang Fang
(Ångström Chemistry, Uppsala Univerisity)
The τ-phase MnAl alloys are promising candidate for rare earth free permanent magnets. In this study, In order to better understand the MnAl ε→τ phase transition mechanism in a continuous cooling process and metastable MnAl τ-phase high temperature stability, Mn0.54Al0.46, Mn0.55Al0.45C0.02 and Mn0.55Al0.45B0.02 alloys were systematically studied by in situ synchrotron X-ray powder diffraction...
Mrs
Diana Lucia Quintero Castro
(University of Stavanger)
Exotic quantum-spin states and quantum phase transitions can be induced in strongly correlated electron systems by applying magnetic fields. In this circumstance the dimerized spin-1/2 quantum antiferromagnet Sr3Cr2O8 is of particular interest, because a magnonic Bose-Einstein condensation [Phys. Rev. Lett. 103, 207203 (2009)] and a coherent magnonic liquid [Phys. Rev. Lett. 116, 147201...
Prof.
Kim Lefmann
(University of Copenhagen)
We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La$_2$CuO$_{4+y}$.
We find that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. We conclude that the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated...
Mr
Tim Tejsner
(Copenhagen University and Institut Laue-Langevin)
The compound La2-xSrxCuO4 (LSCO) is superconducting for 0.05 < x < 0.3 and serves as an interesting model-system due to its relatively simple crystalline structure with only one Cu-O layer per unit cell, which is believed to contain the fundamental aspects of superconductivity. Furthermore, LSCO can be doped with interstitial oxygen to form...
Prof.
Bella Lake
(Helmholtz Zentrum Berlin für Materialien und Energie)
Unlike conventional magnets where the magnetic moments are partially or completely static in the ground state, in a quantum spin liquid they remain in collective motion down to the lowest temperatures. The importance of this state is that it is coherent and highly entangled without breaking local symmetries. Such phenomena is usually sought in simple lattices where antiferromagnetic...
Dr
Michel Kenzelmann
(Paul Scherrer Institut)
The application of magnetic fields, chemical or hydrostatic pressure to strongly-correlated electron materials can stabilize electronic phases with different organizational principles. We studied Ce0.95Nd0.05CoIn5 where a spin-density wave exists within the superconducting state [1]. We find evidence for a field-induced quantum phase transition that separates two antiferromagnetic phases with...
Prof.
Patrik Henelius
(Theoretical Physics, KTH)
Spin ices, frustrated magnetic materials analogous to common water ice, have emerged over the past fifteen years as exemplars of high frustration in three dimensions. By analyzing existing experimental data and carefully remeasuring the thermodynamic quantity $\chi T$ we find that in this material, small effective spin-spin exchange interactions compete with the magnetostatic dipolar...
Dr
Claudio Verdozzi
(Department of Physics Lund)
We investigate the action of static and time dependent ring currents in small magnetic nanoclusters described by the Periodic Anderson Model Hamiltonian. Explicitly, we show how steady-state ring currents (induced by a magnetic field perpendicular to the ring plane) modify the magnetic phase diagram of such nanoclusters, and how fast magnetic pulses affect the system magnetization. We
also...
Prof.
Thomas Tybell
(Department of Electronic Systems, NTNU Norwegian University of Science and Technology)
Perovskite oxides are technologically interesting because of their strong structure property coupling, with interesting functional properties ranging from ferromagnetism, ferroelectricity to high-temperature superconductivity. Here we will give an overview of our work on synthesis of atomically smooth (111)-oriented oxides, and discuss the effect of crystalline facet on their electronic...
Prof.
Thomas Tybell
(Department of Electronic Systems, NTNU Norwegian University of Science and Technology)
Perovskite oxides are technologically interesting because of their strong structure property coupling, with interesting functional properties ranging from ferromagnetism, ferroelectricity to high-temperature superconductivity. Here we will give an overview of our work on synthesis of atomically smooth (111)-oriented oxides, and discuss the effect of crystalline facet on their electronic...
Dr
Dimitri Arvanitis
(Physics and Astronomy, Uppsala University)
We present some of the opportunities specifically offered by synchrotron radiation based spectroscopy in the soft x-ray and the VUV spectral domains to characterize the magnetism and electronic structure of materials suitable for spintronic applications. Spintronic materials exploit the intrinsic spin of the electron in addition to the electron charge. We present studies performed at MAX...
Dr
Janusz Sadowski
(MAX IV laboratory, Lund University)
Embedding magnetic nanocrystals in semiconducting materials is one of the ways to overcome the limits of semiconductor spintronic, where no suitable material combining semiconducting properties with room-temperature ferromagnetism has been found so far [1]. On the other hand the canonical material for semiconductor spintronics, i.e. (Ga,Mn)As dilute ferromagnetic semiconductor, can easily be...
Mr
Mikael S. Andersson
(Uppsala University)
We will present results on densely packed maghemite ($\gamma$-Fe$_2$O$_3$) nanoparticles forming a superspin glass state. A superspin glass is a nanoparticle analogy to the atomic spin glass state, much like a superparamagnet is an analogy to a paramagnet. The main experimental technique used to obtain the results was SQUID magnetometry. The results that we present show that the magnetic...
Mr
Christopher Andersen
(Christopher Røhl Andersen)
Multiferroic compounds with the coexistence of magnetic and ferroelectric orders are well known from few transition metal oxides with perovskite crystal structures. Recently, a new family of multiferroic oxides with other crystal structures has been found: *M*$_3$TeO$_6$ (*M* = Co, Mn, Ni).
Ni3TeO6 has shown interesting multiferroic behaviour with its non-centrosymmetric structure and...
Dr
Flora Yakhou
(European Synchrotron Radiation Facility 71 avenue des Martyrs CS 40220 F-38043 GRENOBLE CEDEX 9 FRANCE)
In the framework of the phase I upgrade of the European Synchrotron Radiation Facility (ESRF), a new beamline dedicated to studies with polarised soft X-rays was built. It features in a dedicated branch a very high resolution spectrometer for Resonant Inelastic X-ray Scattering experiments that started operation in July 2015.
RIXS is a powerful photon-in photon-out scattering technique that...
Dr
Santosh Pal
(Institute for Energy Technology - IFE, Kjeller)
**ABSTRACT:**
Serious environmental consequences of the traditional vapor-compression cooling techniques have turned the research efforts towards development of alternative cooling techniques, and the search for materials showing large caloric effect. Magnetic cooling technology is a rapidly growing technology with a potential of becoming more economic, energy efficient and environmental...
36.
Understanding magnetic phenomena in quantum materials through atomic-scale magnetic correlations
Condensed matter contains unimaginably large numbers of electrons in close contact. In the last few decades, research has uncovered an increasing number of materials whose properties evade description by independent-electron models. These ‘quantum materials’ display non-trivial and often spectacular phenomena that result either from collective electronic behaviour or from geometric properties...
Prof.
Kim Lefmann
(University of Copenhagen)
The origin of high temperature superconductivity (HTSC) is still under debate despite thirty years of intensive research. An increasing amount of evidence points to the interplay between the magnetism and superconductivity as the key to solve this puzzle. We have chosen to study one of the cuprate compounds with a relatively simple crystal structure, namely La$_{2-x}$Sr$_x$CuO$_4$. The phase...
