We present data demonstrating that junction-mixing scanning tunneling microscopy (JM–STM) can provide simultaneous picosecond time resolution and nanometer spatial resolution. Experiments were performed on an Au surface with a patterned Ti overlayer. Our measurements under ultrahigh vacuum conditions achieve a spatial resolution of 1 nm using the tunneling currents generated by 20 ps voltage transients. The observed contrast in a JM–STM signal is demonstrated to arise entirely from the difference in electronic structure between the Au and Ti surfaces. These results confirm that JM–STM signals originate in the tunnel junction and maintain the atomic-scale spatial resolution inherent in STM.

The ever-growing demand for hard drives with greater storage density has motivated a technology shift from continuous magnetic media to patterned media hard disks, which are expected to be implemented in future generations of hard disk drives to provide data storage at densities exceeding 1012 bits/in.2. Step and flash imprint lithography (S-FIL) technology has been employed to pattern the hard disk substrates. This article discusses the infrastructure required to enable S-FIL in high-volume manufacturing, namely, fabrication of master templates, template replication, high-volume imprinting with precisely controlled residual layers, and dual-sided imprinting. Imprinting of disks is demonstrated with substrate throughput currently as high as 180 disks/h (dual sided). These processes are applied to patterning hard disk substrates with both discrete tracks and bit-patterned designs.

The type of photocharge carriers in ice was determined by means of an electrolysis technique. It was suggested earlier that irradiation of ice by UV light above 6.5 eV generates positive H3O+ ions, neutral OH• radicals, solvated electrons es -, D defects, and vacancies of water molecules according to the “autoionization” reaction. Is the photoconductivity (PC) observed purely “protonic”, due to motion of H3O+ ions and D defects, or does it have an additional electron component related to the motion of solvated electrons es - or their analogies? The presence of the electron component should not produce any additional gas release near the electrodes during an electrolysis process and for that reason can be easily detected as a deviation from Faraday's law of electrolysis. We found that the amount of gas released per coulomb of charge flow is the same with or without the UV light. Therefore, the UV light does not change the composition (the proportion) of mobile charge carriers in ice, and in 25% of our tests the PC directly demonstrates a purely protonic nature. We also concluded that solvated electrons do not participate in the dc conductivity of ice. Probable reasons are discussed for the absence of a 100% gas release rate when the density of electric currents was below 100 μA/cm.

It is found that the electric conductivity of ice changes appreciably upon its illumination in the vacuum ultraviolet spectral region. The changes observed have reversible and persistent parts (after switching off light). Spectral and kinetic characteristics of the photoconductivity (PC) of ice are presented. A PC maximum corresponds to a photon energy hv ≈ 6.8 eV. The dependence of the reversible part of PC on the water purification techniques is studied. It is assumed that the phenomenon observed is independent of the impurity contents and in this sense PC is intrinsic. Special investigations are devoted to possible photoelectric phenomena at the ice‐‐electrode interfaces. A monotoneous accumulation of small quantities of H2O2 in ice is observed when increasing the light exposition. This is an evidence for the participation of “free” radicals OH. in the PC processes. It is concluded that conduction electrons and Bjerrum defects (L‐ und D‐defects) cannot be nonequilibrium charge carriers.

A method of photoelectromotive force (PEMF) was developed to find the charge sign, mobility, and lifetime of photo charge carriers in ice generated by photons with energy h v> 6.5 e V. It was determined that the most mobile photo charge carriers are negative ones, with mobility JL increasing from 2X 10-3 cm 2 N s at T= -10 DC to 4X 10-2 cm 2 N s at T= -30 DC, and with their lifetime decreasing from 30 to 10 s in the same temperature range. Activation energies of the mobility and the lifetime are Ep.= -0.77 eV and Er=0.32 eV, respectively. In addition to the negative photo charge carriers positive ones arise with mobility ,u=2.3 X 10-4 cm 2 N s and lifetime 7=26 min at T= -15 DC. We suggest that the negative photo charge carriers in ice are mobile complexes of an electron, vacancy and D-defect (e -+ V + D). To take into account a specific mechanism of charge transport in ice, configurational vector n, and the generation of complexes (e -+ V + D), a reaction of "autoionization" was modified for ice, 2H 2 0+hv-.H 3 0+ +OH;"ie-+ V+ D).