To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
NiO is a typical material for new p-type oxide semiconductors. Conductivity of NiO can be raised with Li+ doping. In case of Li-heavy doping, we can obtain LixNiO2(0.5< × <1.0). Recently the importance of LiNiO2 has been increased as an electrode material for rechargeable lithium cells.
In this work, we tried to fabricate a novel NiO material with Li+-heavily doped by applying the pulsed laser-induced room temperature (R.T.) film process. Previously, we have succeeded in the epitaxial growth of various oxide thin films at R.T. such as Sn-doped In2O3 transparent electrodes . Although the many studies have been made on the deposition of NiO epitaxial thin film at low temperatures , there are few reports on fabrication and the conductive characteristic for Li-heavily doped NiO epitaxial films. The film deposition at R.T., which is the unequilibrium vapor phase process, is expected to result in different crystal structure and characteristics from the films grown at high-temperatures.
A composition-adjusted thin film of LixNi1-xO(0.10< × <0.40) was deposited on a sapphire (α-Al2O3)(0001) or MgO(100) substrates by pulsed laser deposition (PLD) technique in 10−6 Torr of oxygen at R.T. and the high temperatures of 350 and 515°C. Crystalline properties of thin films deposited at R.T. or high temperatures were examined using reflection high energy electron diffraction (RHEED) and X-ray diffraction. For the Li-heavily doped NiO films(x>0.30) grown at R.T., a clear streak RHEED pattern showing epitaxial growth was observed. But the Li-heavily doped NiO films grown at high temperatures, exhibited the ring RHEED pattern, which indicates the policrystal growth of films. Electric conductivity of various Li-doped NiO thin films deposited at R.T. or high temperatures on sapphire (0001) substrates were measured by two-probe method. The interesting results were obtained that conductivity of the film was increased remarkably with an increase of Li-doping for R.T. deposition, but was not changed so much regardless of Li-doping for high-temperature depositions.
We introduce the lasing principle and important characteristics of photonic-crystal surface-emitting laser (PC-SELs). Specifically, we demonstrate two-dimensional coherent lasing oscillation with GaN PC-SELs, using a unique crystal growth technique called “air hole retained overgrowth” (AROG). Above the threshold, we obtained a two-dimensionally distributed near-field pattern, and a distinctive far-field pattern with a divergence angle less than 1°. We also investigate a suitable sample structure for the reduction of the threshold current, where the PC structure is moved from an n-cladding layer to a p-cladding one. This is an important step towards the realization of novel light sources that can be integrated two dimensionally for a variety of new scientific and engineering applications in the blue to ultraviolet wavelengths.
The crystal growth of lanthanum hexaboride (LaB6) thin films was examined by applying the laser molecular beam epitaxy (laser MBE) process. C-axis (100) highly-oriented LaB6 thin films could be fabricated on ultrasmooth sapphire (α-Al2O3 single crystal) (0001) substrates with atomic steps of 0.2 nm in height and atomically flat terraces. The obtained film exhibited a smooth surface with root mean square roughness of 0.15 nm. The lattice parameter of the LaB6 thin film was close to the bulk value reported previously. In the case of deposition on commercial mirror-polished sapphire substrates, the grown film was amorphous. The resistivity of the prepared crystalline LaB6 thin films was as low as 2.2 × 10−4 Ω cm and almost constant in the temperature range of 10–300 K.
It is shown by direct numerical simulation that the preferential concentration of small heavy particles in homogeneous isotropic developed turbulence has a self-similar multi-scale nature when the particle relaxation time is within the inertial time scales of the turbulence. This is shown by the pair correlation function of the particle distribution extending over the entire inertial range, and the probability density function of the volumes of particle voids taking a power-law form. This self-similar multi-scale nature of particle clustering cannot be explained only by the centrifugal effect of the smallest-scale (i.e. the Kolmogorov scale) eddies, but also by the effect of co-existing self-similar multi-scale coherent eddies in the turbulence at high Reynolds numbers. This explanation implies that the preferential concentration of particles takes place even when the relaxation time of particles is much larger than the Kolmogorov time, provided it is smaller than the longest time scale of the turbulence, since even the largest-scale eddies bring about particle clustering.
Email your librarian or administrator to recommend adding this to your organisation's collection.