相关论文: Ferromagnetic insulating state in tensile-strained…
LaCoO3 thin films grown under epitaxial tensile strain exhibit a robust ferromagnetic insulating state that is absent in the bulk. Despite many studies, both experimental and computational, the microscopic origin of this phenomenon is not…
At ambient pressure, bulk SrCoO$_{3}$ is a ferromagnetic (FM) metal in cubic perovskite structure. By contrast, magnetic properties of epitaxial SrCoO$_{3}$ thin films, especially at high tensile strain ($\varepsilon \gtrsim 3$\%), remain…
The origin of insulating ferromagnetism in epitaxial LaCoO3 films under tensile strain remains elusive despite extensive research efforts have been devoted. Surprisingly, the spin state of its Co ions, the main parameter of its…
We study ferromagnetic ordering and microscopic inhomogeneity in tensile strained LaCoO$_3$ using numerical simulations. We argue that both phenomena originate from effective superexchange interactions between atoms in the high-spin (HS)…
Inspired by the experimental findings of an exotic ferromagnetic insulating state in LaMnO$_3$/SrTiO$_3$ heterostructures, we calculate the electronic and magnetic state of LaMnO$_3$/SrTiO$_3$ superlattices with comparable thicknesses…
Epitaxial strain in transition-metal oxides can induce dramatic changes in electronic and magnetic properties. A recent study on the epitaxially strained SrCoO$_3$ thin films revealed persistent ferromagnetism even across a metal-insulator…
Epitaxial thin films of LaCoO_{3} (E-LCO) exhibit ferromagnetic order with a transition temperature T_c = 85 K, while polycrystalline thin LaCoO_{3} films (P-LCO) remain paramagnetic. The temperature-dependent spin-state structure for both…
The electronic structure of epitaxial films on LaCoO3(LCO) has been studied within first principle electronic structure calculations. A spin state transition is found to take place as a function of lattice strain which freezes in the…
We present LDA+$U_{sc}$ calculations of high-spin (HS) and low-spin (LS) states in ferropericlase (fp) with an iron concentration of 18.75$\%$. The Hubbard parameter $U$ is determined self-consistently with structures optimized at arbitrary…
We present evidence for the coexistence of ferromagnetic metallic and charge ordered insulating phases in strained thin films of La$_{0.67}$Ca$_{0.33}$MnO$_3$ at low temperatures. Such a phase separated state is confirmed using low…
The enigma of the emergent ferromagnetic state in tensile-strained LaCoO3 thin films remains to be explored because of the lack of a well agreed explanation. The direct magnetic imaging technique using a low-temperature magnetic force…
Bulk magnetization in Pr_{0.6}Ca_{0.4}MnO_3 thin films with tensile (SrTiO_3) and compressive (LaAlO_3) substrate-induced strain is compared to the magnetooptical Kerr effect (MOKE) measurements. In the absence of an external magnetic…
We studied the Co valences and spin states in electron-doped LaCo$_{1-y}$Te$_{y}$O$_3$ by measuring x-ray absorption spectra and electron spin resonance. The low-temperature insulating state involves the low-spin Co$^{3+}$ ($S=0$) and the…
Ferromagnetic insulators play a crucial role in the development of low-dissipation quantum magnetic devices for spintronics. Epitaxial LaCoO3 thin film is a prominent ferromagnetic insulator, in which the robust ferromagnetic ordering…
Compressed Pr0.5Ca0.5MnO3 films (250nm) deposited on LaAlO3 have been studied by Electron Spin Resonance technique under high frequency and high magnetic field. We show evidences for the presence of a ferromagnetic phase (FM) embedded in…
The spin states of Co$^{3+}$ ions in perovskite-type LaCoO$_3$, governed by complex interplay between the electron-lattice interactions and the strong electron correlations, still remain controversial due to the lack of experimental…
Using spectroscopic ellipsometry, we studied the optical conductivity of LaCoO$_3$ with various degrees of strain. The optical response of the compressively strained \lco\ film is qualitatively similar to the one of the unstrained LaCoO$_3$…
We report on the observation of a strain-induced insulator state in ferromagnetic La_0.7Sr_0.3CoO_3 films. Tensile strain above 1% is found to enhance the resistivity by several orders of magnitude. Reversible strain of 0.15% applied using…
We investigate the structure and magnetic properties of thin films of the LaCoO$_{3}$ compound. Thin films are deposited by pulsed laser deposition on various substrates in order to tune the strain from compressive to tensile. Single-phase…
The electronic structure of the perovskite La$_{1-x}$Sr$_x$CoO$_3$ has been obtained as a function of Sr substitution and volume from a series of generalized-gradient-corrected, full-potential, spin-density-functional band structure…