Room temperature charge-ordered phase in Gd0.6Ca0.4MnO3 and Sm0.6Ca0.4MnO3 thin films

Strain-Induced Domain Structure and Its Impact on Magnetic and Transport Properties of Gd0.6Ca0.4MnO3 Thin Films

“…The typical zero-field-cooled (ZFC) and field-cooled (FC) temperature dependence of magnetizations are measured with an external magnetic field of 50 mT applied parallel to the film surface (Figure a). As reported in the previous literature, ,, at low temperature, the net magnetization of GCMO components is due to the Gd spins and the Mn spins, which are oriented antiparallel with each other. As temperature increases, the magnetic moments of the Mn ions dominate, reaching a maximum at around 50 K. The strength of the maximum depends on the Mn 4+ /Mn 3+ ratio, lattice distortion, and oxygen content in the perovskite lattice. ,, In our case, the maximum for the GCMO/STO film has lower values compared to that for the GCMO/LSAT and the GCMO/SLAO films.…”

“…The mixed-valence A 1– x B x MnO 3 perovskite manganites, where A and B are rare-earth and divalent alkaline elements, have recently become the focus of extensive research due to their unusual magnetic and magnetoresistance properties. − Among the perovskites, the low-bandwidth manganites, such as Pr 1– x Ca x MnO 3 (PCMO) and Gd 1– x Ca x MnO 3 (GCMO), are particularly interesting due to the stable charge ordering (CO) state in the whole doping range, leading to several important features like resistive switching and spin memory effect. − Moreover, the Gd-based low-bandwidth perovskites not only show the CO state near room temperature but also exhibit specific magnetic features, particularly the reversal magnetization at low temperature and in the applied magnetic field, leading to a ferrimagnetic ground state. − The structural and physical properties of such materials are strongly dependent on the deposition technique and the lattice mismatch with the substrate, which results in uniaxial strain. − The strain can be responsible for phase separation , and modification of the relation between the lattice parameters in the direction perpendicular to growth ( c ) and the one in the parallel plane ( a ) . On the other hand, the fabrication of high-quality perovskite thin films by controlling the strain and the lattice mismatch between the bulk and substrate can affect the electrical and magnetic properties of manganites. , …”

Metastable ferromagnetic flux closure-type domains in strain relaxed Gd0.1Ca0.9MnO3 thin films

“…The ceramic polycrystalline Gd 0.1 Ca 0.9 MnO 3 (GCMO) target for pulsed laser deposition (PLD) was prepared by a solid state reaction method [12]. Initially, Gd 2 O 3 oxide was calcined at 1300 • C for 12 h in air and, on the other hand, CaCO 3 and MnO 2 were dried at 200 • C in air.…”

“…Electrical transport properties were measured in a 9 T quantum design physical properties measurement system utilizing four Au probe electrodes deposited by DC-magnetron sputtering on top of the films with a distance between the electrodes of 250 μm. Gold was chosen as an electrode material because it forms an ohmic junction with the GCMO samples, if low enough bias is applied [12]. Magnetization of the samples was measured by a quantum design MPMS SQUID magnetometer.…”

Electron Doping Effect in the Resistive Switching Properties of Al/Gd1–xCaxMnO3/Au Memristor Devices

“…The elemental compositions of the samples were verified using energy-dispersive spectroscopy, which showed compositions similar to the nominal values and no systematic deviation . More details on the fabrication process and XRD analysis can be found in refs and .…”