D. Berling

Co2FeAl thin films grown on MgO substrates: Correlation between static, dynamic, and structural properties

Co2FeAl (CFA) thin films with thickness varying from 10 nm to 115 nm have been deposited on MgO(001) substrates by magnetron sputtering and then capped by Ta or Cr layer. X-rays diffraction (XRD) revealed that the cubic

Deep ultraviolet laser direct write for patterning sol-gel InGaZnO semiconducting micro/nanowires and improving field-effect mobility

[001]

Room-temperature ferromagnetism in single crystal Fe1.7Ge thin films of high thermal stability grown on Ge(111)

CFA axis is normal to the substrate and that all the CFA films exhibit full epitaxial growth. The chemical order varies from the

Epitaxial magnetic Fe layers grown on Si(001) by means of a template method

B2

Magnetization reversal mechanisms in epitaxial Fe/Si(001) layers with twofold and fourfold magnetic anisotropies

phase to the

Epitaxial Fe-Ge thin films on Ge(111): Morphology, structure, and magnetic properties versus stoichiometry

A2

Static and dynamic magnetic properties of epitaxial Fe1.7Ge thin films grown on Ge(111)

phase when decreasing the thickness. Magneto-optical Kerr effect (MOKE) and vibrating sample magnetometer measurements show that, depending on the field orientation, one or two-step switchings occur. Moreover, the films present a quadratic MOKE signal increasing with the CFA thickness, due to the increasing chemical order. Ferromagnetic resonance, MOKE transverse bias initial inverse susceptibility and torque (TBIIST) measurements reveal that the in-plane anisotropy results from the superposition of a uniaxial and of a fourfold symmetry term. The fourfold anisotropy is in accord with the crystal structure of the samples and is correlated to the biaxial strain and to the chemical order present in the films. In addition, a large negative perpendicular uniaxial anisotropy is observed. Frequency and angular dependences of the FMR linewidth show two magnon scattering and mosaicity contributions, which depend on the CFA thickness. A Gilbert damping coefficient as low as 0.0011 is found.

Chemical and structural investigation of zinc-oxo cluster photoresists for DUV lithography

Deep-UV (DUV) laser was used to directly write indium-gallium-zinc-oxide (IGZO) precursor solution and form micro and nanoscale patterns. The directional DUV laser beam avoids the substrate heating and suppresses the diffraction effect. A IGZO precursor solution was also developed to fulfill the requirements for direct photopatterning and for achieving semi-conducting properties with thermal annealing at moderate temperature. The DUV-induced crosslinking of the starting material allows direct write of semi-conducting channels in thin-film transistors but also it improves the field-effect mobility and surface roughness. Material analysis has been carried out by XPS, FTIR, spectroscopic ellipsometry and AFM and the effect of DUV on the final material structure is discussed. The DUV irradiation step results in photolysis and a partial condensation of the inorganic network that freezes the sol-gel layer in a homogeneous distribution, lowering possibilities of thermally induced reorganization at the atomic scale. Laser irradiation allows high-resolution photopatterning and high-enough field-effect mobility, which enables the easy fabrication of oxide nanowires for applications in solar cell, display, flexible electronics, and biomedical sensors.

Effect of obliquely evaporated Au cap layer on the magnetic properties of thin Fe films on Si(111)

We report on the epitaxial growth of ultrathin ferromagnetic Fe1.7Ge layers on Ge(111) wafer. These single crystal intermetallic layers adopt the InNi2 (B82) crystallographic structure. They are ferromagnetic with a Curie temperature well above room temperature. The interface between the ferromagnet layer and the Ge wafer is of high perfection. Interestingly, the annealing of the sample up to 300°C alters neither the crystallographic structure, nor the interface quality, nor the magnetic properties but leads to a nearly perfect smoothening of the germanide layer surface. This high thermal robustness should open the way for the growth of fully epitaxial iron germanide/Ge hybrid structures.

Evidence of a ternary Co1-xFexSi2 phase with a CaF2-type structure: High-resolution transmission electron microscopy and diffraction anomalous fine structure study

We demonstrate the possibility of growing good-quality epitaxial Fe films on a Si(001) substrate, opening up new prospects to prepare ferromagnetic superlattices on this substrate. A template technique prevents the formation of disordered interfacial iron silicides. Transmission electron microscopy reveals that the Fe layers are fairly uniform in thickness with abrupt interfaces and in majority epitaxial relationship Fe(001)[100]//Si(001)[100]. Both the diffraction data and the observation of Moire fringes indicate that the Fe lattice is almost relaxed towards its bulk bcc phase in thick layers [≥40 monolayers (ML)] but is still strained by the substrate in the thinnest films. Magneto-optical Kerr effect measurements show that the films evaporated at normal incidence with a thickness above 4 ML are ferromagnetic at room temperature and exhibit in-plane biaxial anisotropy.