Anisotropic strains, metal-insulator transition, and magnetoresistance of La0.7Ca0.3MnO3 films
نویسنده
چکیده
Thin films of perovskite manganite La0.7Ca0.3MnO3 were grown epitaxially on various substrates by either the pulsed laser deposition method or laser molecular beam epitaxy. The substrates change both the volume and symmetry of the unit cell of the films. It is revealed that the symmetry as well as the volume of the unit cell have strong influence on the metal-insulator transition temperature and the size of magnetoresistance.
منابع مشابه
Anisotropic strains and magnetoresistance of La0.7Ca0.3MnO3
Thin films of perovskite manganite La0.7Ca0.3MnO3 were grown epitaxially on SrTiO3(100), MgO(100) and LaAlO3(100) substrates by the pulsed laser deposition method. Microscopic structures of these thin film samples as well as a bulk sample were fully determined by x-ray diffraction measurements. The unit cells of the three films have different shapes, i.e., contracted tetragonal, cubic, and elon...
متن کاملUnusual ferromagnetism enhancement in ferromagnetically optimal manganite La0.7−yCa0.3+yMn1−yRuyO3 (0≤y<0.3): the role of Mn-Ru t2g super-exchange
The eg-orbital double-exchange mechanism as the core of physics of colossal magnetoresistance (CMR) manganites is well known, which usually covers up the role of super-exchange at the t2g-orbitals. The role of the double-exchange mechanism is maximized in La0.7Ca0.3MnO3, leading to the concurrent metal-insulator transition and ferromagnetic transition as well as CMR effect. In this work, by a s...
متن کاملخواص ساختاری، الکتریکی و مغناطیسی منگنایتLa1-xCaxMnO3
Manganites are considered as subbranches of condensed matter physics with a great wealth of physical mechanisms. In this investigation we have studied the structural, electrical and magnetic properties of a series of La1-xCaxMnO3 manganite with x=0.1, 0.2, …,0.5. We observed that the crystal structure of this manganite, with small dopping, at room temperature is orthorhombic and by increasi...
متن کاملSpin valve effect across the metal-insulator transition in V2O3
The magnetoresistance of Ni/V2O3/Py devices shows interesting behavior in the temperature dependence across the V2O3 metal-insulator transition. A spin-valve effect ( 0.1%) is found below the transition temperature when V2O3 is in the insulating phase. Contrary to expectation, the spin-valve effect disappears when device is heated above 150 K and V2O3 is in the metallic state. At these temperat...
متن کاملMagnetoresistive Effect in PET Films with Iron Nanoparticles Synthesized by Ion Implantation
Thin polyethyleneterephthalate (PET) layers with Fe nanoparticles (NPs) were synthesized by high-fluence ion implantation. Temperature dependence of conductance and magnetoresistance, were studied as a function of ion fluence. It is found that the implantation with fluences of about 1.0×10 cm causes high enough concentration of metal inclusions to provide conditions for electrical percolation t...
متن کامل