27 research outputs found
The effects of spin-orbit coupling on optical properties of monolayer MoS 2 due to mechanical strains
Abstract We have studied the optical conductivity of a quasi two-dimensional MoS 2 in the presence of external magnetic field and spin-orbit coupling. Specially, we address the frequency dependence of optical conductivity due to spin-orbit interaction. Using linear response theory the behavior of optical conductivity has been obtained within Greenâs function method. We have also considered the effects of uniaxial and biaxial in-plane strain on the optical absorption of MoS 2 layer. In the absence of external magnetic field with negative uniaxial strain parameter, optical conductivity includes Drude weight at zero frequency limit while Drude weight vanishes for MoS 2 layer under positive uniaxial strain. Our results show that the increase of uniaxial positive strain parameter causes to move the position peak to the higher frequencies. In contrast to uniaxial strain case, the Drude weight in optical conductivity appears at positive biaxial strain value 0.15. Also we have studied the effects of magnetic field, electron doping, hole doping in the presence of spin-orbit coupling on frequency dependence of optical conductivity of MoS 2 in details. The magnetic field dependence of optical absorption shows a monotonic decreasing behavior for each value of temperature in the absence of strain parameter
Bifunctional FePt@MWCNTs/Ru nanoarchitectures: Synthesis and characterization
The synthesis of novel nanoarchitectures is an important way to combine several properties into the same nanometric object. Magnetic, catalytic, optical, and electrical properties can be embedded and used for heating, moving, or monitoring the nanocomposite. Following this approach, smart materials exhibiting remarkable properties could be obtained. Several nanocomposites are based on carbon nanotubes (CNTs). Because of the presence of empty cavities and very large surface external area, this allotropic form of carbon is especially suitable for this purpose and particularly for catalytic applications. In this work, a new general strategy to synthesize by a wet method three-block, smart nanocomposites based on MWCNTs is described. The new bifunctional material is shortly referred to as FePt@MWCNTs/Ru(NPs) to point out that nanoparticles (NPs) of a magnetically soft alloy (FePt fcc) fill the MWCNTs cavity, whereas catalytic Ru NPs decorate the external wall. In this way well separated catalytic and magnetic NPs are obtained. All the synthetic steps are described in detail. TEM, HRTEM, XRD, and magnetic measurements by VSM are used to monitor all the steps and to prove the effectiveness of the metho
Microstructure and optical properties of cobaltâcarbon nanocomposites prepared by RF-sputtering
International audienc
Bifunctional FePt@MWCNTs/Ru Nanoarchitectures: Synthesis and Characterization
The synthesis of novel nanoarchitectures is an important
way to
combine several properties into the same nanometric object. Magnetic,
catalytic, optical, and electrical properties can be embedded and
used for heating, moving, or monitoring the nanocomposite. Following
this approach, smart materials exhibiting remarkable properties could
be obtained. Several nanocomposites are based on carbon nanotubes
(CNTs). Because of the presence of empty cavities and very large surface
external area, this allotropic form of carbon is especially suitable
for this purpose and particularly for catalytic applications. In this
work, a new general strategy to synthesize by a wet method three-block,
smart nanocomposites based on MWCNTs is described. The new bifunctional
material is shortly referred to as FePt@MWCNTs/RuÂ(NPs) to point out
that nanoparticles (NPs) of a magnetically soft alloy (FePt fcc) fill
the MWCNTs cavity, whereas catalytic Ru NPs decorate the external
wall. In this way well separated catalytic and magnetic NPs are obtained.
All the synthetic steps are described in detail. TEM, HRTEM, XRD,
and magnetic measurements by VSM are used to monitor all the steps
and to prove the effectiveness of the method