The multilevel switching of conductive bridge resistive memory is characterized by the ON-state resistance (R ON ) being inversely proportional to the compliance current (I CC ). The constant of this relation is shown to be universally correlated to the minimum SET voltage (V SETðminÞ ) for all conductive bridge devices. V SETðminÞ , required to switch the memory from high resistance state to low resistance state, can be extracted using small voltage sweep rates. The correlation has been verified by experiments on Cu/TaO x /Pt devices and confirmed for data on resistive devices reported in the literature. The physical domain of validity for the R ON -I CC relation has been established.

This paper introduces a new synthesis procedure to form erbium-doped ceria nanoparticles (EDC NPs) that can act as an optical medium for both up-conversion and down-conversion in the same time. This synthesis process results qualitatively in a high concentration of Ce3+ ions required to obtain high fluorescence efficiency in the down-conversion process. Simultaneously, the synthesized nanoparticles contain the molecular energy levels of erbium that are required for up-conversion. Therefore, the synthesized EDC NPs can emit visible light when excited with either UV or IR photons. This opens new opportunities for applications where emission of light via both up- and down-conversions from a single nanomaterial is desired such as solar cells and bio-imaging.

A phenomenological model has been proposed for the radial growth of the copper or silver nanobridge in the conductive bridge random access memory devices. In this model, the growth rate of the bridge is proportional to the local ion flux based on the hopping mechanism. Due to the differences of the local electric field, the growth rate is different along a conical shape nanobridge. The model accounts for the growth rate difference by introducing a geometrical form factor. Based on the model, the top and bottom radii are predicted for truncated conical copper nanobridge. The model is validated with data obtained on Cu/TaO x /Pt resistive devices.

Conductive bridge random access memory (CBRAM) shows strong potential for replacing flash memory on the sub-20 nm technology nodes. The switching mechanism is primarily attributed to the electrochemical formation and rupture of conductive filaments. In Cu/TaOx/Pt devices, high electric current in the RESET process can cause significant local heating. Thomson heating effect has to be considered due to conical or cylindrical filament geometries giving cause for strong temperature gradients. The thermoelectric effect is evaluated for the Cu and oxygen vacancy nanofilaments in bipolar and unipolar switching modes. The Thomson coefficient for oxygen vacancy filament is extracted from the difference of SET voltages between two switching modes.

Gas chromatography is a technology that is constantly moving forward. The current trend for this field is moving towards miniaturizing the columns towards achieving high-speed separations. Groups are constantly researching different geometries, topographies, and stationary phases in order to make these separations more efficient. In order to achieve this goal of increased efficiency, we have taken two ideas from previous works, namely being width modulated channels as well as semi-packed columns, and tried to use the redeeming qualities that exist in both and combine them to achieve something that shares their positive points. Semi-packed columns have been shown to increase the plate height for a column. However, the pressure drop that occurs in these types is a significant drawback that makes high-speed separations very difficult to achieve with lower inlet pressures. Width modulation of the column channel can be used to change the overall velocity of the gas as it travels throughout the column resulting in a lower overall pressure drop. The method that was used to combine these two ideas was to change the density of the pillars in the semi-packed column along the length of the channel to achieve the same effect of the width modulation. This was achieved by changing the number of pillars across in the channel as well as the pitch distance between sets of pillars. Controls were also fabricated so the results could be compared to the two extreme designs. After extensive testing, the results indicated that between the minimum and maximum density, the maximum density allowed only ~50% of the total flow that the minimum density design showed at the same inlet pressure. In comparison, the design that changed pillar density throughout the channel allowed ~89% of the flow the minimum density design. This is a significant increase in flow and allows for much more to pass through the chip in a given time span increasing the efficiency of high-speed separations. The other factor that was tested for was the number of theoretical plates for each of the designs. It was shown through testing with a constant sample that the minimum density column behaves very similarly to an open column without pillars whereas the density modulated column has plate numbers between those of the minimum density and the maximum density. This is even further data that supports the use of a pillar density modulated chip for high-speed separations.