buletinul institutului politehnic din iaşi bulletin of the polytechnic ...

GALVANOMAGNETIC EFFECTS OF NEW CoFeSiBMo ALLOY
BY
MIHAI LOZOVAN, HORIA CHIRIAC, VIOREL DOBREA,
MIHAIL-LIVIU CRAUS, SERGIU MOHORIANU
Abstract. Results concerning measurements of the Hall resistivity, spontaneous Hall
coefficient, longitudinal and transversal magnetoresistance and ferromagnetic anisotropic
resistivity for as-cast and thermally treated Co 65.75 Fe 4.5 Si 12.25 B 15 Mo 2.5 amorphous ribbons
are presented. The obtained results show a strong dependence of the electrical properties of
the samples on the thermal treatment. In the nanocrystallized samples the value of
ferromagnetic anisotropic resistivity (+1.65·10 –4 ) is quite similar to that of the amorphous
samples (+1.17·10 –4 ). In the crystallized state the value of ferromagnetic anisotropic
resistivity increases up to +17.93·10 –4 .
Key words: magnetoresistance, Hall effect, ferromagnetic anisotropic resist- ivity
CORE SHELL PHOSPHORESCENT COMPOSITES APPLIED
IN OPTOELECTRONICS
BY
CORNELIU STAN, MARIUS SEBASTIAN SECULA,
DANA TUTULEA, DOINA SIBIESCU, IOAN ROŞCA, IGOR CREłESCU
Abstract. In the present paper, beside a brief literature review concerning the
fabrication of some illumination systems based on phosphorescent composites, some
polymeric matrices based on PET and co-polymeric PET/PEG, very promising for the
lighting-source applications, are also presented. The specific advantages of these polymers
(high thermal and UV stability, high transparency, high melting and transition temperatures
and lack of toxicity) represent the fundaments for obtaining new composites with
phosphorescent properties adapted to the requirements of their applications. Also, some
experimental tests were performed in order to achieve some PET and co-polymeric
PET/PEG matrices aiming at enhancing phosphorescent nanocomposite performances.
Key words: phosphorescent nanocomposite, quantum dot, polymeric matrix,
PET/PEG block copolymer.