29 research outputs found
magnetic measurements based on magneto optical kerr effect on pnictide ba fe1 x cox 2as2 fe thin film
We present characterization of Ba(Fe1−x Cox)2As2 thin film using a magneto-optical Kerr effect setup based on photoelastic modulation. The magneto optical technique has been used to analyse the thickness and the temperature dependence of the magnetic properties of epitaxial Ba(Fe1−x Cox)2As2/Fe thin films grown on MgO substrate. The first harmonics, of the reflected laser beam intensity from pnictide thin films is compared with a reference Fe thin film. The hysteretic loops of such samples at room temperature and at 5K are presented
Magnetic measurements based on magneto-optical Kerr effect on pnictide Ba(Fe1?xCox)2As2/Fe thin film
We present characterization of Ba(Fe1-x Cox) 2As2 thin film using a magneto-optical Kerr effect setup based on photoelastic modulation. The magneto optical technique has been used to analyse the thickness and the temperature dependence of the magnetic properties of epitaxial Ba(Fe1-x Cox)2As2/Fe thin films grown on MgO substrate. The first harmonics, of the reflected laser beam intensity from pnictide thin films is compared with a reference Fe thin film. The hysteretic loops of such samples at room temperature and at 5K are presented
Magnetic measurements based on magneto-optical Kerr effect on pnictide Ba(Fe 1−x
We present characterization of Ba(Fe1−x Cox)2As2 thin film using a magneto-optical Kerr effect setup based on photoelastic modulation. The magneto optical technique has been used to analyse the thickness and the temperature dependence of the magnetic properties of epitaxial Ba(Fe1−x Cox)2As2/Fe thin films grown on MgO substrate. The first harmonics, of the reflected laser beam intensity from pnictide thin films is compared with a reference Fe thin film. The hysteretic loops of such samples at room temperature and at 5K are presented
Beam divergence of high-order harmonics generated in the few-optical cycle regime
The beam divergence of high-order harmonics generated in Helium by an ultra-short Ti:sapphire laser (7 fs and 30 fs) is experimentally characterized by means of a flat-field, high-resolution spectrometer. The harmonic beam divergence is also analysed as a function of the gas-jet position relative to the laser beam waist. Results, which are partly different from previous measurements performed at longer laser pulse duration, are discusse
Probing the Reaction Mechanism of Aluminum/Poly(vinylidene fluoride) Composites
Energetic
thin films with high mass loadings of nanosized components have been
recently fabricated using electrospray deposition. These films are
composed of aluminum nanoparticles (nAl) homogeneously dispersed in
an energetic fluoropolymer binder, polyÂ(vinylidene fluoride) (PVDF).
The nascent oxide shell of the nAl has been previously shown to undergo
a preignition reaction (PIR) with fluoropolymers such as polytetraÂfluoroÂethylene
(PTFE). This work examines the PIR between alumina and PVDF to further
explain the reaction mechanism of the Al/PVDF system. Temperature
jump (T-jump) ignition experiments in air, argon, and vacuum environments
showed that the nAl is fluorinated by gas phase species due to a decrease
in reactivity in a vacuum. Thermogravimetric analysis coupled with
differential scanning calorimetry (TGA/DSC) was used to confirm the
occurrence of a PIR, and gas phase products during the PIR and fluorination
of nAl were investigated with temperature jump time-of-flight mass
spectrometry (T-jump TOFMS). Results show a direct correlation between
the amount of alumina in the PVDF film and the relative signal intensity
of hydrogen fluoride release (HF). Although the PIR between alumina
and PVDF plays an important role in the Al/PVDF reaction mechanism,
burn speeds of Al/PVDF films containing additional pure alumina particles
showed no burn speed enhancement