Volume 125, Issue 12, 28 September 2006
Index of content:
125(2006); http://dx.doi.org/10.1063/1.2353814View Description Hide Description
We demonstrate a two-color reduced-Doppler probe for ion imaging that, in many applications, offers advantages over conventional resonance-enhanced multiphoton ionization detection. Using counterpropagating beams of two different colors, one of which is broadband , we achieve convenient and sensitive D atom detection without the need for Doppler scanning. We demonstrate the approach using photodissociation of DBr. This method improves the sensitivity and signal-to-noise ratio and presents advantages and opportunities for use in the other systems.
125(2006); http://dx.doi.org/10.1063/1.2354080View Description Hide Description
Spin-polarized electronic and transport properties of carbon atomic chains are investigated when they are capped with magnetic transition-metal (TM) atoms like Cr or Co. The magnetic ground state of the chains alternates between the ferromagnetic (F) and antiferromagnetic (AF) spin configurations as a function of . In view of the nanoscale spintronic device applications the desirable AF state is obtained for only even- chains with Cr; conversely only odd- chains with Co have AF ground states. When connected to appropriate metallic electrodes these atomic chains display a strong spin-valve effect. Analysis of structural, electronic, and magnetic properties of these atomic chains, as well as the indirect exchange coupling of the TM atoms through non-magnetic carbon atoms are presented.
Second-order overtone and combination modes in the LOLA region of acid treated double-walled carbon nanotubes125(2006); http://dx.doi.org/10.1063/1.2354081View Description Hide Description
Moderate acid treatment of double-walled carbon nanotubes (DWCNTs) has given rise to two new experimentally observed second-order double resonant Raman scattering frequencies centered at and , in the highly dispersive LOLA region. These LOLA overtones and combination modes have been predicted by double resonance theory for two phonons associated with the - and -points, respectively.