Materials science: Changing face of the chameleon

  title={Materials science: Changing face of the chameleon},
  author={Alan Lindsay Greer and Neil D Mathur},
Chalcogenide materials form the basis of CD and DVD technologies. But an identity crisis looms in the wider field: what role do atomic reconfiguration, electronic processes and ionic movement play in these materials? 
Growth and Characterization of Amorphous Multicomponent Nitride Thin Films
This thesis explores deposition of amorphous thin films based on the two transition metal nitride systems, TiN and HfN. Additions of Si, Al and B have been investigated using three different deposi
Coexistence of tetrahedral- and octahedral-like sites in amorphous phase change materials
Chalcogenide alloys are materials of interest for optical recording and nonvolatile memories. We perform ab initio molecular dynamics simulations aiming at shading light onto the structure of
Controlling light on the nanoscale with chalcogenide thin films
The phase change technology behind rewritable optical disks and the latest electronic memory storage devices has provided clear commercial and technological advances for the field of data storage.
Pressure-induced site-selective disordering of Ge2Sb2Te5: a new insight into phase-change optical recording.
We demonstrate that , the material of choice in phase-change optical recording (such as DVD-RAM), can be rendered amorphous by the application of hydrostatic pressure. It is argued that this
Fabrication of phase-change chalcogenide Ge2Sb2Te5 patterns by laser-induced forward transfer.
Results show multi-level electrical and optical reflection states of the fabricated patterns, which may provide a simple and efficient foundation for patterning future phase-change devices.
Phase change gallium and germanium chalcogenides for optical electronic and plasmonic switching
We show that the phase-change technology behind rewritable optical disks and the latest generation of electronic memories can also offer applications in active plasmonics and metamaterials. A range
Evidence for electronic gap-driven metal-semiconductor transition in phase-change materials
Correlations between conductivity, total system energy, and local atomic coordination revealed by experiments and long time ab initio simulations show that the structural reorganization into the amorphous state is driven by opening of an energy gap in the electronic density of states.
Molecular dynamics study of amorphous Ga-doped In2O3: A promising material for phase change memory devices
In this paper, we employ the ab-initio molecular dynamics simulations, within the framework of density functional theory, to construct and characterize the amorphous structure of gallium-doped indium
Nanoscale Bipolar Electrical Switching of Ge2Sb2Te5 Phase‐Change Material Thin Films
Chalcogenide phase‐change materials (PCMs) exhibit distinct rapid changes in electrical properties upon repeatable switching between amorphous and crystalline structure and are thus attractive for


Ovonics : From science to products
Ovshinsky's pioneering work and inventions in amorphous chalcogenide semiconductor materials in the 1960s invigorated an entire field of physics. The electronic switching he first demonstrated has
Nanoscale memory elements based on solid-state electrolytes
We report on the fabrication and characterization of nanoscale memory elements based on solid electrolytes. When combined with silver, chalcogenide glasses such as Se-rich Ge-Se are good solid
Threshold Switching in Chalcogenide-Glass Thin Films
The application of sufficiently high electric fields to any material eventually results in deviations from linearity in the observed current-voltage I(V) characteristic. There are two general classes
Quantized conductance atomic switch
It is demonstrated that a quantized conductance atomic switch (QCAS) can switch between ‘on’ and ‘off’ states at room temperature and in air at a frequency of 1 MHz and at a small operating voltage (600 mV).
Phase-change recording medium that enables ultrahigh-density electron-beam data storage
An ultrahigh-density electron-beam-based data storage medium is described that consists of a diode formed by growing an InSe/GaSe phase-change bilayer film epitaxially on silicon. Bits are recorded
Low-cost and nanoscale non-volatile memory concept for future silicon chips
The feasibility of a new semiconductor memory concept that promises that integration into a logic complementary metal oxide semiconductor (CMOS) process flow might be possible with only a few additional lithographic steps is demonstrated.
Reversible Electrical Switching Phenomena in Disordered Structures
We describe here a rapid and reversible transition between a highly resistive and a conductive state effected by an electric field which we have observed in various types of disordered materials,
Optical cognitive information processing: A new field
I will discuss unique electronic and structural mechanisms of Ovonic optical phase-change devices making possible orders of magnitude increase of density of memory and introducing multiple