相关论文: The centrifugal Jahn-Teller effect in rare-earth c…
The Crystalline Electric Field (CEF) influence is usually described by considering an ideally symmetrical rare-earth site. In the case of cage compounds, ample excursions of the rare-earth inside the cage require an adapted CEF description.…
Rare-earth (RE) based compounds and alloys are of great interest both for their fundamental physical properties and for applications. In order to tailor the required compounds for a specific task, one must be able to predict the energy…
In some intermetallic compounds, the crystallographic structure allows for an unusual latitude of movement of lanthanide ions inside so-called cages. Examples of such magnetic cage systems include the rare-earth hexaborides RB6 and filled…
In rare-earth cage compounds, the guest 4f ion cannot be considered as fixed at the centre of its cage. As result of the electronic degeneracy of the 4f shell, single-ion or collective mechanisms can redistribute the ion inside the cage,…
The properties of transition metal compounds are largely determined by nontrivial interplay of different degrees of freedom: charge, spin, lattice, but also orbital ones. Especially rich and interesting effects occur in systems with orbital…
Dynamical Jahn-Teller effect has escaped so far direct observation in metallic systems. It is particularly believed to be quenched also in correlated conductors with orbitally degenerate sites such as cubic fullerides. Here the Gutzwiller…
Few materials undergo cooperative Jahn-Teller (JT) transitions at low temperatures, but zircon-type oxides are one class that includes DyVO$_4$, which transforms from a tetragonal to an orthorhombic structure at around 13.6 K, with a narrow…
Contribution to thermal conductivity from conduction electron scattering on crystal field magnetic excitations is calculated and analyzed for normal rare-earth inter-metallic paramagnets. It is shown that in temperatures much lower than…
The Jahn-Teller effect is a fascinating and ubiquitous phenomenon in modern quantum physics and chemistry. We propose a class of oxides with melilite structure Ba$_2$TGe$_2$O$_7$ (T=V,Ni) where Jahn-Teller distortions are the main…
The electronic properties of many transition metal oxide systems require new ideas concerning the behaviour of electrons in solids for their explanation. A recent example, subsequent to that of cuprate superconductors, is of rare earth…
An influence of high magnetic fields on hyperfine interaction in the rare-earth ions with non-magnetic ground state (Van Vleck ions) is theoretically investigated for the case of $Tm^{3+}$ ion in axial symmetrical crystal electric field…
It is shown that the d8 electron system occurring in the Ni2+ ion can have the non-magnetic ground state in the atomic scale formed by the Jahn-Teller effect. The tetragonal/trigonal off-cubic lattice distortion for the octahedral site…
The calculation of magnetic anisotropy constants is performed beyond the point charge model for a continuous charge density distribution of screening conduction electrons. An important role of the non-uniform electron density, in…
The formation of a long-range Jahn-Teller distortion in undoped manganites is studied within the dynamical mean-field theory taking both electron-phonon and electron-electron interactions into account. We find that the observed insulating…
We analyze the influence of unconventional superconductivity on crystalline electric field (CEF) excitations of rare earth ions in novel superconductors. We show that resonant magnetic excitations of the conduction electrons that have been…
Central Compact Objects are peculiar young neutron stars, with very low external magnetic fields combined with high fluxes in the X-ray band and surface temperature anisotropies. However, in their crust the magnetic field can be strong,…
We investigate the low-temperature magnetic and quantum properties of hexanuclear Fe$^ {3+}_6$ complexes under an external magnetic field. We primarily study the impact of competing exchange interactions and their asymmetries induced by the…
The magnetocaloric effect (MCE) in many rare earth (RE) based intermetallic compounds has been extensively investigated during last two decades, not only due to their potential applications for magnetic refrigeration but also for better…
The crystalline electric field (CEF) is investigated in Pr$_3$Pt$_{23}$Si$_{11}$ and Nd$_3$Pt$_{23}$Si$_{11}$ by neutron spectroscopy (NS). At low temperature, the number of observed CEF excitations is consistent with the orthorhombic…
We present a theory describing the single-ion anisotropy of rare earth (RE) magnets in the presence of point defects. Taking the RE-lean 1:12 magnet class as a prototype, we use first-principles calculations to show how the introduction of…