6 research outputs found
A view of the implanted SiC damage by Rutherford backscattering spectroscopy, spectroscopic ellipsometry, and transmission electron microscopy
4H-SiC single crystalline substrates were implanted at room temperature with 150 keV Al+ ions
using fluences of 4 1014, 1 1015, and 2 1015 cm−2 with current density of 2.5 A cm−2. The
samples were subsequently annealed at 1100 °C in N2 for 1 h in order to analyze their structural
recovery. The disorder induced in both sublattices by the Al+ ions was studied by backscattering
spectrometry in channeling geometry with a 3.5 MeV He2+ beam. The results were compared with
the optical properties of the samples measured by spectroscopic ellipsometry. In a previous work,
we concluded that during the postimplantation annealing of a highly damaged SiC crystalline
material the short distance order can be recovered, while the long distance disorder remains. We also
presented the possibility to have grains of different polytypes oriented faraway from the original
direction. Now, this alternative is confirmed by the cross-sectional transmission and high resolution
electron microscopy studies, carried out to obtain information about the crystal structure.Ministerio de Cienncias y Tecnología español-MAT2002-02843 (70% de fondos FEDER)Acuerdo de Colaboración Científica Húngaro-Españo-lE27 / 2001Fondo de Investigaciones Científicas de Hungría (OTKA)-T032029, T047011, T043704 y K6172
Magnetic calorimeter for registration of small energy release
A scheme of magnetic calorimeter for registration of rare events characterized by small energy release (cosmic rays, WIMPs, solitary X-ray quanta) is proposed. The calorimeter is brought to operation by adiabatic demagnetization, and its magnetic response is measured by a quantum interferometer (SQUID, A. Barone and G. Paterno, Physics and applications of Josephson Effect). Special consideration is given to the specific features of calorimeter operation in the ferromagnetic transition region. The trigger registration of ultrasmall energy release by a ferromagnetic system in the metastable state is described. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200775.30.Sg Magnetocaloric effect, magnetic cooling, 85.25.Dq Superconducting quantum interference devices (SQUIDs),