39 research outputs found
Thermopower peak in phase transition region of (1-x)LaCaMnO/xYSZ
The thermoelectric power (TEP) and the electrical resistivity of the
intergranular magnetoresistance (IGMR) composite,
(1-x)LaCaMnO/xYSZ (LCMO/YSZ) with x = 0, 0.75%, 1.25%,
4.5%, 13% 15% and 80% of the yttria-stabalized zirconia (YSZ), have been
measured from 300 K down to 77 K. Pronounced TEP peak appears during the phase
transition for the samples of x 0, while not observed for x = 0. We suggest
that this is due to the magnetic structure variation induced by the lattice
strain which is resulting from the LCMO/YSZ boundary layers. The transition
width in temperature derived from , with being the AC magnetic
susceptibility, supports this interpretation.Comment: 4 pages, 4 eps figures, Latex, J. Appl. Phys 94, 7206 (2003
Selective on/off switching at room temperature of a magnetic bistable {Fe2Co2} complex with single crystal-to-single crystal transformation via intramolecular electron transfer
National Nature Science Foundation of China [21172084, 20802022]; Self-determined research funds of CCNU from the colleges' basic research and operation of MOE [CCNU13F006, CCNU11C01002]A cyano-bridged {Fe2Co2} complex shows reversible single crystal-to-single crystal transformation between diamagnetic and paramagnetic states switched specifically by losing and absorbing methanol at room temperature in the solid state. And the solvent loss form presents temperature- and pressure-induced intramolecular electron transfer behaviour
Landau level splitting in Cd3As2 under high magnetic fields
Three-dimensional topological Dirac semimetals (TDSs) are a new kind of Dirac
materials that exhibit linear energy dispersion in the bulk and can be viewed
as three-dimensional graphene. It has been proposed that TDSs can be driven to
other exotic phases like Weyl semimetals, topological insulators and
topological superconductors by breaking certain symmetries. Here we report the
first transport experiment on Landau level splitting in TDS Cd3As2 single
crystals under high magnetic fields, suggesting the removal of spin degeneracy
by breaking time reversal symmetry. The detected Berry phase develops an
evident angular dependence and possesses a crossover from nontrivial to trivial
state under high magnetic fields, a strong hint for a fierce competition
between the orbit-coupled field strength and the field-generated mass term. Our
results unveil the important role of symmetry breaking in TDSs and further
demonstrate a feasible path to generate a Weyl semimetal phase by breaking time
reversal symmetry.Comment: 31 page