920 research outputs found
Effect of strain on the transport properties of the manganite systems
The effect of strain on the resistivity and thermopower of ferromagnetic
manganites has been examined based on the model that incorporates the
electron-lattice interaction through the Jahn-Teller effect and an effective
hopping determined by nearest neighbour spin-spin correlation of t2g electrons.
The metal insulator transition temperature associated with resistivity
decreases with increase in strain. In the presence of large strain the system
remains in the semiconducting state. Thermopower (S) is positive and increasing
function of strain and it exhibits a maximum with temperature. The temperature
where maximum of S appears, shifts towards higher (lower) value with in the
presence of magnetic field (strain). A large magneto-thermopower that depends
on strain is obtained around metal-insulator transition.Comment: 11pages, 4 figure
Magnetic Field and Displacement sensor based on Giant Magneto-impedance effect
A two-core transducer assembly using a Fe73.5Nb3Cu1Si13.5B9 ribbon to detect
a change of magnetic field is proposed and tested for displacement (linear and
angular) and current sensor. Two identical inductors, with the ribbon as core,
are a part of two series resonance network, and are in high impedance state
when excited by a small a.c field of 1MHz in absence of d.c biasing field
(Hdc). When the magnetic state of one inductor is altered by biasing field,
produced by a bar magnet or current carrying coil, an ac signal proportional to
Hdc is generated by transducer. The results for the sensitivity and linearity
with displacement (linear and angular) of a magnet and with field from the
current carrying coil are presented for two particular configurations of the
transducer. High sensitivities of voltage response as much as
12micro-volt/micro-meter and 3mV/degree have been obtained for the transducer
as a linear and angular displacement sensor respectively in the transverse
configuration of exciting a.c and biasing d.c fields.Comment: 16 pages,7 figure
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