Electron holography on HfO2/HfO2-x bilayer structures with multilevel resistive switching properties.

Unveiling the physical nature of the oxygen-deficient conductive filaments (CFs) that are responsible for the resistive switching of the HfO2-based resistive random access memory (RRAM) devices represents a challenging task due to the oxygen vacancy related defect nature and nanometer size of the CFs. As a first important step to this goal, we demonstrate in this work direct visualization and a study of physico-chemical properties of oxygen-deficient amorphous HfO2-x by carrying out transmission electron microscopy electron holography as well as energy dispersive x-ray spectroscopy on HfO2/HfO2-x bilayer heterostructures, which are realized by reactive molecular beam epitaxy. Furthermore, compared to single layer devices, Pt/HfO2/HfO2-x /TiN bilayer devices show enhanced resistive switching characteristics with multilevel behavior, indicating their potential as electronic synapses in future neuromorphic computing applications.

Treatment of giant cell tumor of the distal radius by ulnar translocation. A case report and review of the literature.

Presented is a case of giant cell tumor of the distal radius treated successfully by en bloc resection and translocation of the ipsilateral distal ulna. A good functional result was achieved with near full range of pronation and supination and 5 degrees of flexion at the wrist. The advantage of this technique is that the ulna provides a locally available vascularized graft to bridge the gap created by resection of the radius.