Two-terminal multistate memory elements based on VO(2)/TiO(2) thin film microcantilevers are reported. Volatile and non-volatile multiple resistance states are programmed by current pulses at temperatures within the hysteretic region of the metal-insulator transition of VO(2). The memory mechanism is based on current-induced creation of metallic clusters by self-heating of micrometric suspended regions and resistive reading via percolation.

We report on the isotropic pinning obtained in epitaxial Fe(Se,Te) thin films grown on CaF2(001) substrate. High critical current density values - larger than 1 MA/cm(2) in self field and liquid helium - are reached together with a very weak dependence on the magnetic field and a complete isotropy. Analysis through transmission electron microscopy evidences the presence of defects looking like lattice disorder at a very small scale, between 5 and 20 nm, which are thought to be responsible for such isotropic behavior in contrast to what was observed on SrTiO3, where defects parallel to the c-axis enhance pinning in that direction

By applying a negative voltage to the conducting tip of an atomic force microscope, we modify on submicron-scale semiconducting oxygen deficient SrTiO3−δ thin films grown on LaAlO3 substrates. In comparison with the as-grown film, the modified regions present different electrical and structural properties, which can be exploited to realize submicrometer circuits. After a discussion on the mechanisms of the process, we report a prototype of a SrTiO3−δ-based sidegate field-effect transistor, showing a 4% modulation of channel resistivity with gate voltages up to 40 V.

A programmable micromechanical resonator based on a VO2 thin film is reported. Multiple mechanical eigenfrequency states are programmed using Joule heating as local power source, gradually driving the phase transition of VO2 around its Metal-Insulator transition temperature. Phase coexistence of domains is used to tune the stiffness of the device via local control of internal stresses and mechanical properties. This study opens perspectives for developing mechanically configurable nanostructure arrays.

Transition-Metal Oxides (TMO) are of great technological impact due to the numerous properties they exhibit, like superconductivity, ferroelectricity and piezoelectricity, dielectricity, semiconductivity, orbital and spin ordered phases, and fully spin-polarized current. Their rich phase diagrams are determined by coupling of spin, charge, and lattice degrees of freedom, whose interplay can be modified by doping, external fields and lattice strain. In TMO, the transition-metal d-orbitals play the game; as a consequence of the strong local interactions, the phase diagrams strongly depend on the overlapping, the occupancy, and the fluctuations of the atomic orbitals.[1] In this scenario, lattice strain is one of the most powerful parameters to achieve control of TMO functionalities. Biaxial strains up to a few percent have been achieved on TMO thin films by changing the substrate lattice constant or by chemical doping, triggering phase transitions and modulating transition temperatures. [2][3][4][5][6][7][8][9] The real contribution of strain is often hindered by spurious effects arising from the growth mechanisms, and is not reversible. [10,11] In order to clarify these issues and move toward applications, active modulation of strain in crystalline TMOs thin films has been achieved by mechanical apparata [12] or by epitaxial locking with ferropiezoelectric substrates [13][14][15][16][17][18] or thin films. [19,20] The maximum attained voltage-assisted biaxial in-plane strain modulation, mainly compressive, is currently limited to about À0.25%. [21] Different approaches for strain manipulation of oxides also exploit the mechanical coupling between oxide nanocomposites [22,23] or the bending of oxide nanobeams and nanowires. [24,25] Nevertheless, bending of thin epitaxial TMO films is still an unexplored terrain. The objective of this work is to produce strain on TMO films by combining crystalline TMO thin films with microelectromechanical systems (MEMS) concepts. In particular, we show a MEMS device that employs mechanical deformations to induce tensile strain on a functional oxide film. So far, despite the enormous strategic interest of smart devices, few works on functional oxide MEMS and free-standing oxide structures have been reported, [26][27][28][29][30] mainly for applications as bolometers, mostly grown on buffer silicon substrates. Employment of piezoelectric ZnO or ferroelectric Pb(Zr 1 Ti)O 3 films for sensing or actuation of silicon cantilevers for atomic force microscopy (AFM) [31] and resistive strain gauges based on polycrystalline binary oxide films have been also reported.[32]Here, we show micro-electromechanical structures entirely based on crystalline perovskites that can be employed as ''strain-generator devices'' for a wide class of epitaxial oxide films. A crystalline suspended bridge of the most common substrate for TMOs deposition, SrTiO 3 (STO), is used as flexible substrate for the deposition of functional epitaxial TMO thin films. This element is bent both mechanically by an AFM tip and...