相关论文: Phase transition close to room temperature in BiFe…
We report a study on the thermodynamic stability and structure analysis of the epitaxial BiFeO3 (BFO) thin films grown on YAlO3 (YAO) substrate. First we observe a phase transition of MC-MA-T occurs in thin sample (<60 nm) with an utter…
We combine a wide variety of experimental techniques to analyze two heretofore mysterious phase transitions in multiferroic bismuth ferrite at low temperature. Raman spectroscopy, resonant ultrasound spectroscopy, EPR, X-ray lattice…
Temperature evolution of dielectric response, atomic structure, and lattice dynamics in thin film of sodium niobate in the epitaxial NaNbO$_3$/SrRuO$_3$/(001)MgO heterostructure is studied by dielectric measurements, x-ray diffraction, and…
The structure and microstrucutre of fully-strained BiCrO3 thin films have been investigated by X-rays diffraction and transmission electron microscopy, at room temperature. Interestingly, three structural variants are simultaneously…
We have studied the cubic to tetragonal phase transition in epitaxial SrTiO$_3$ films under various biaxial strain conditions using synchrotron X-ray diffraction. Measuring the superlattice peak associated with TiO$_6$ octahedra rotation in…
Recent studies have reported the existence of an epitaxially-stabilized tetragonal-like ('T-like') monoclinic phase in BiFeO3 thin-films with high levels of compressive strain. While their structural and ferroelectric properties are…
Epitaxial Mn-doped BiFeO3 (MBFO) thin films were grown on GaAs (001) substrate with SrTiO3 (STO) buffer layer by pulsed laser deposition. X-ray diffraction results demonstrate that the films show pure (00l) orientation, and…
We show that epitaxial (001) thin films of multiferroic bismuth ferrite BiFeO3 are monoclinic at room temperature instead of tetragonal or Rhombohedral as reported earlier . We report a orthorhombic order-disorder beta-phase between 820C…
Single phase (001)-oriented BiFeO3 (BFO) thin films grown by pulsed laser deposition can only be obtained in a narrow window of deposition pressure and temperature and have a low magnetic moment. Out of the stability window Fe- or Bi-rich…
We demonstrate room temperature ferroelectricity in the epitaxial thin films of magnetoelectric GaFeO3. Piezo-force measurements show a 180o phase shift of piezoresponse upon switching the electric field indicating nanoscale…
Multiferroic BiFeO3 (BFO) thin film exhibiting desired ferroelectric and enhanced magnetic properties was grown on La0.67Sr0.33MnO3 (LSMO) buffered Pt/TiO2/SiO2/Si substrates by off-axis RF magnetic sputtering, where a highly (111)-oriented…
We develop a phenomenological thermodynamic theory of ferroelectric BaTiO3 (BT) thin films epitaxially grown on cubic substrates using the Landau-Devonshire eight-order potential. The constructed "misfit-temperature" phase diagram is…
Multiferroics with the coexistence of ferroelectric and ferromagnetic orders are ideal candidates for magnetoelectric applications. Unfortunately, only very few ferroelectric-ferromagnetic multiferroics (with low magnetic critical…
Room-temperature magnetoelectric multiferroicity has been observed in c-axis oriented GaFeO$_3$ thin films (space group $Pna2_1$), grown on economic and technologically important (100)Si substrates by pulsed laser deposition technique.…
We report on the functionalization of multiferroic BiFeO3 epitaxial films for spintronics. A first example is provided by the use of ultrathin layers of BiFeO3 as tunnel barriers in magnetic tunnel junctions with La2/3Sr1/3MnO3 and Co…
Al2O3 thin films have been deposited at substrate temperatures between 500{\deg}C to 600{\deg}C by reactive magnetron sputtering using an additional arbitrary substrate bias to tailor the energy distribution of the incident ions. The films…
The magnetic and transport properties of BiFeO3/La2NiMnO6 (BFO/LNMO) composite have been investigated both experimentally and theoretically. Unlike the normal rhombohedral (R3c) phase, BFO in the composites is crystallized in the triclinic…
We present evidence for a concomitant structural and ferroelectric transformation around $T_S\sim 360$ K in multiferroic BiFeO$_3$/LaAlO$_3$ thin films close to the tetragonal phase. Phonon excitations are investigated by using Raman…
We have grown epitaxial thin films of multiferroic BiMnO$_3$ using pulsed laser deposition. The films were grown on SrTiO$_3$ (001) substrates by ablating a Bi-rich target. Using x-ray diffraction we confirmed that the films were epitaxial…
Thin films of (1-x)BiFeO<sub>3</sub>-xPbTiO<sub>3</sub> (BF-xPT) with x ~ 0.60 were fabricated on Pt/Si substrates by chemical solution deposition of precursor BF and PT layers alternately in three different multilayer configurations. These…