A study on the kinetic arrest of magnetic phases in nanostructured NdSrMnOthin films.

The NdSrMnO(NSMO) manganite system exhibits a phase transition from paramagnetic insulating (PMI) to ferromagnetic metallic (FMM) state around its Curie temperature= 270 K (bulk). The morphology-driven changes in the kinetically arrested magnetic phases in NSMO thin films with granular and crossed-nano-rod-type morphology are studied. The manganite thin films at low temperatures possess a magnetic glassy state arising from the coexistence of the high-temperature PMI and the low-temperature FMM phases.

The effect of charged particle irradiation on the transport properties of bismuth chalcogenide topological insulators: a brief review.

Topological insulators (TIs) offer a novel platform for achieving exciting applications, such as low-power electronics, spintronics, and quantum computation. Hence, the spin-momentum locked and topologically nontrivial surface state of TIs is highly coveted by the research and development industry. Particle irradiation in TIs is a fast-growing field of research owing to the industrial scalability of the particle irradiation technique.

Highly Porous Polypyrrole (PPy) Hydrogel Support for the Design of a Co-N-C Electrocatalyst for Oxygen Reduction Reaction.

Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have emerged as one of the most promising platinum-group metal (PGM)-free cathode catalysts for oxygen reduction reaction (ORR). Among the various approaches to enhance the ORR performance of the catalysts, increasing the density of accessible active sites is of paramount importance. Thus, nitrogen-rich support with abundant porosity can be very propitious.

Tuning of the Thermoelectric Properties of BiTe Nanorods Using Helium Ion Irradiation.

The present study reports an enhancement of the power factor of BiTe nanorods NRs) by helium (He) ion irradiation. High-resolution transmission electron microscopy studies revealed the formation of amorphous layers on the surface of the NRs at the high ion fluence. This amorphous nature is due to the accumulation of migrating point defect clusters at the surface of the NRs.

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO nanostructures of various morphologies.

One-dimensional (1D) SnO sub-wavelength waveguides are a critical contribution to advanced optoelectronics. Further understanding of the surface defects and role of morphology in 1D SnO nanowires can help to better utilize these nanostructures more efficiently. For this purpose, three different nanowires (NWs), namely belts, cylindrical- and square-shaped structures were grown using SnO quantum dots as a precursor material.

High-Pressure Synthesis of Manganese Monocarbide: A Potential Superhard Material.

In this paper, we report for the first time formation of novel manganese monocarbide (MnC) using laser-heated diamond anvil cell (LHDAC). The synthesis was carried out at high pressure-high temperature (HPHT) and subsequently quenched to ambient condition. The formation and reproducibility have been confirmed in the pressure range of 4.

An insight into the origin of room-temperature ferromagnetism in SnO and Mn-doped SnO quantum dots: an experimental and DFT approach.

SnO and Mn-doped SnO single-phase tetragonal crystal structure quantum dots (QDs) of uniform size with control over dopant composition and microstructure were synthesized using the high pressure microwave synthesis technique. On a broader vision, we systematically investigated the influence of dilute Mn ions in SnO under the strong quantum confinement regime through various experimental techniques and density functional theoretical (DFT) calculations to disclose the physical mechanism governing the observed ferromagnetism. DFT calculations revealed that the formation of the stable (001) surface was much more energetically favorable than that of the (100) surface, and the formation energy of the oxygen vacancies in the stable (001) surface was comparatively higher in the undoped SnO QDs.

Process-specific mechanisms of vertically oriented graphene growth in plasmas.

Applications of plasma-produced vertically oriented graphene nanosheets (VGNs) rely on their unique structure and morphology, which can be tuned by the process parameters to understand the growth mechanism. Here, we report on the effect of the key process parameters such as deposition temperature, discharge power and distance from plasma source to substrate on the catalyst-free growth of VGNs in microwave plasmas. A direct evidence for the initiation of vertical growth through nanoscale graphitic islands is obtained from the temperature-dependent growth rates where the activation energy is found to be as low as 0.

Photoluminescence of oxygen vacancies and hydroxyl group surface functionalized SnO2 nanoparticles.

We report, for the first time, the luminescence property of the hydroxyl group surface functionalized quantum dots (QDs) and nanoparticles (NPs) of SnO2 using low energy excitations of 2.54 eV (488 nm) and 2.42 eV (514.

Quantification of oxide particle composition in model oxide dispersion strengthened steel alloys.

Oxide dispersion strengthened ferritic steels (ODS) are being considered for structural components of future designs of fission and fusion reactors because of their impressive high-temperature mechanical properties and resistance to radiation damage, both of which arise from the nanoscale oxide particles they contain. Because of the critical importance of these nanoscale phases, significant research activity has been dedicated to analysing their precise size, shape and composition (Odette et al., Annu.

Valence state, hybridization and electronic band structure in the charge ordered AlV2O4.

The valence state, hybridization and electronic band structure of charge ordered AlV2O4 are investigated by measuring the electron energy loss spectra (EELS) and performing band structure calculations using the WIEN2k code. White line ratio and O K edges of V2O5, VO2, V2O3 and AlV2O4, obtained using electron energy loss spectroscopy, are analysed specifically to probe systematically the VO6 octahedra in all of them. The systematic decrease of the L2 intensity and the O K edge intensity from V(5+) in V2O5 to AlV2O4 indicates a progressive increase in the occupancy of the hybridized states, which is corroborated by the absence of a transition from O 1s to hybridized 2t(2g).

A high resolution scanning electron microscope for in situ investigation of swift heavy ion induced modification of solid surfaces.

A new in situ high resolution electron microscope (HRSEM) setup has been designed and integrated into the materials science beamline (M-branch) of the universal linear accelerator at Gesellschaft für Schwerionenforschung, Darmstadt for in situ investigations of swift heavy ion induced surface modifications. Special ports for in situ experiments are installed at the HRSEM chamber to connect it to the high vacuum beamline, which is equipped with suitable beam control and shaping devices. In order to demonstrate the feasibility and power of this new instrument, first experiments were performed on a 50-nm-thick Fe(2)O(3) film on Si substrate, which exhibited submicrometer size holes due to irradiation induced dewetting in a previous experiment.

Structure and photoluminescence properties of ion beam synthesized SiC nanoparticles in Si.

Silicon carbide nanoparticles were synthesized in Si(100) wafers by 300 keV C+ ion implantation at elevated substrate temperatures of 550, 650 and 700 degrees C. The implantation has been carried out upto a fluence of 2 x 10(17) ions/cm2 with a constant current density 1.2 microA/cm2.

Implantation induced hardening of nanocrystalline titanium thin films.

Formation of nanocrystalline TiN at low temperatures was demonstrated by combining Pulsed Laser Deposition (PLD) and ion implantation techniques. The Ti films of nominal thickness approximatly 250 nm were deposited at a substrate temperature of 200 degrees C by ablating a high pure titanium target in UHV conditions using a nanosecond pulsed Nd:YAG laser operating at 1064 nm. These films were implanted with 100 keV N+ ions with fluence ranging from 1.

Si(+) ion irradiation in a Co/Pt multilayer system.

This paper deals with a study of the effect of Si(+) ion irradiation on a Co/Pt multilayer system irradiated at different temperatures. The as-deposited and irradiated samples have been characterized using x-ray reflectivity (XRR), x-ray diffraction (XRD) and the magneto-optical Kerr effect (MOKE). X-ray reflectivity shows clear intermixing at the interfaces.