4 research outputs found
Synthesis of a Complex Prototype Ladder Filter Excluding Inductors with Finite Transmission Zeros Suitable for Fully Differential Gm-C Realization
In this letter, an active complex filter with finite transmission zeros is proposed. In order to obtain a complex prototype ladder filter including no inductors, a new circuit transformation is proposed. This circuit is classified into the RiCR filter. It is shown that it includes no negative capacitors when it is obtained through a frequency transformation. The validity of the proposed method is confirmed through computer simulation
Evolution of the Fe-3 impurity band state as the origin of high Curie temperature in p-type ferromagnetic semiconductor (Ga,Fe)Sb
(Ga,Fe)Sb is one of the promising ferromagnetic semiconductors
for spintronic device applications because its Curie temperature ()
is above 300 K when the Fe concentration is equal to or higher than ~0.20.
However, the origin of the high in (Ga,Fe)Sb remains to be
elucidated. To address this issue, we use resonant photoemission spectroscopy
(RPES) and first-principles calculations to investigate the dependence of
the Fe 3 states in (Ga,Fe)Sb ( = 0.05, 0.15, and 0.25) thin
films. The observed Fe 2-3 RPES spectra reveal that the Fe-3 impurity
band (IB) crossing the Fermi level becomes broader with increasing , which
is qualitatively consistent with the picture of double-exchange interaction.
Comparison between the obtained Fe-3 partial density of states and the
first-principles calculations suggests that the Fe-3 IB originates from the
minority-spin () states. The results indicate that enhancement
of the interaction between electrons with increasing is the
origin of the high in (Ga,Fe)Sb