Related papers: Magnetite: Raman study of the high-pressure and lo…
We report high-pressure low-temperature Raman studies of the Verwey transition in pure and Al-doped magnetite (Fe_3O_4). The low temperature phase of magnetite displays a number of additional Raman modes that serve as transition markers.…
We investigated the electronic and vibrational properties of magnetite at temperatures from 300 K down to 10 K and for pressures up to 10 GPa by far-infrared reflectivity measurements. The Verwey transition is manifested by a drastic…
We present infrared and Raman measurements of magnetite (Fe_3O_4). This material is known to undergo a metal-insulator and a structural transition (Verwey transition) at T_V=120K. At temperatures below T_V, we observe a strong gap-like…
We provide evidence for the existence of a {\em quantum critical point} at the metallization of magnetite Fe$_{3}$O$_{4}$ at an applied pressure of $p_{c} \approx 8$ GPa. We show that the present ac magnetic susceptibility data support…
We have studied experimentally the responses of high quality single crystals of stoichiometric synthetic magnetite to applied weak dc and ac magnetic fields in the range of 6 K to 60 K, far below the Verwey transition. The results can be…
A controlled point-like disorder induced by low temperature 2.5 MeV electron irradiation was used to probe the nature of the Verwey transition in magnetite, $\text{Fe}_{3}\text{O}_{4}$. Two large single crystals, one with optimal transition…
We incorporate single crystal Fe$_3$O$_4$ thin films into a gated device structure and demonstrate the ability to control the Verwey transition with static electric fields. The Verwey transition temperature ($T_V$) increases for both…
The multiferroic manganese tungstate (MnWO4) has been studied by high-pressure Raman spectroscopy at room temperature under quasi-hydrostatic conditions up to 39.3 GPa. The low-pressure wolframite phase undergoes a phase transition at 25.7…
Magnetite (Fe3O4) is of fundamental importance as the original magnetic material and also for the Verwey transition near T_V = 125 K, below which a complex lattice distortion and electron orders occur. The Verwey transition is suppressed by…
We have studied the electronic structure and charge ordering (Verwey) transition of magnetite (Fe3O4) by soft x-ray photoemission. Due to the enhanced probing depth and the use of different surface preparations we are able to distinguish…
By combining {\it ab initio} results for the electronic structure and phonon spectrum with the group theory, we establish the origin of the Verwey transition in Fe$_3$O$_4$. Two primary order parameters with $X_3$ and $\Delta_5$ symmetries…
We have monitored the Verwey transition in micrometer-wide, nanometer-thick magnetite islands on epitaxial Ru films on Al2O3(0001) using Raman spectroscopy. The islands have been grown by high-temperature oxygen-assisted molecular beam…
We report on the finite size effects in the Verwey transition of stress-free magnetite Fe3O4 thin films. A limit thickness of 20 nm is evidenced, above which the transition temperature TV is constant and close to 120 K (bulk value) and…
Neutron diffraction experiments on TmTe at pressures up to 7 GPa are reported. The semiconductor-to-metal transition occurring at 2 GPa in this compound is accompanied by the appearance of strong ferromagnetic exchange interactions…
Effects of the Verwey transition on the (100) surface of magnetite were studied using scanning tunelling microscopy and spin polarized low-energy electron microsccopy. On cooling through the transition temperature Tv, the initially flat…
Resistance measurements on single crystals of CaK(Fe$_{1-x}$Mn$_x$)$_4$As$_4$ ($x$ = 0.024) were performed under hydrostatic pressure up to 5.15 GPa. The pressure dependence of the magnetic and superconducting transition temperatures and…
We report Raman scattering data of single crystals of magnetite (Fe3O4) with Verwey transition temperatures (Tv) of 123 and 117K, respectively. Both single crystals reveal broad electronic background extending up to 900 wavenumbers (~110…
We develop a variational mean-field theory of the ferromagnetic transition in compounds like Lanthanum-Manganite within the framework of the Double-Exchange Model supplemented by modest disorder. We obtain analytical expressions for the…
We have carried out a detailed high-pressure investigation on the strongly correlated transition metal chalcogenide $Cr_{3}Te_4$ using Raman spectroscopy and XRD, which is ferromagnetic and metallic at ambient conditions. We find that the…
Contact effects in devices incorporating strongly-correlated electronic materials are comparatively unexplored. We have investigated the electrically-driven phase transition in magnetite (100) thin films by four-terminal methods. In the…