159 research outputs found
Ferromagnetic ground state of the robust charge-ordered manganite Pr(0.5)Ca(0.5MnO(3)obtained by minimal Al-substitution
We show that minimal disturbance to the robust charge ordered
Pr(0.5)Ca(0.5)MnO(3) by 2.5% Al substitution on Mn-site drives the system
towards ferromagnetic ground state. The history-dependent coexisting phases
observed are explained as an outcome of a hindered first order transition with
glass like arrest of kinetics resulting in irreversibility. Consistent with a
simple phase diagram having ferromagnetic ground state, it is experimentally
shown that these coexisting phases are far from the equilibrium.Comment: This version is Accepted in Physical Review
Kinetic Arrest of Field-Temperature Induced First Order Phase Transition in Quasi- One Dimensional Spin System Ca3Co2O6
We have found that the geometrically frustrated spin chain compound Ca3Co2O6
belonging to Ising like universality class with uniaxial anisotropy shows
kinetic arrest of first order intermediate phase (IP) to ferrimagnetic (FIM)
transition. In this system, dc magnetization measurements followed by different
protocols suggest the coexistence of high temperature IP with equilibrium FIM
phase in low temperature. Formation of metastable state due to hindered first
order transition has also been probed through cooling and heating in unequal
field (CHUF) protocol. Kinetically arrested high temperature IP appears to
persist down to almost the spin freezing temperature in this system.Comment: Kinetic arrest of first order magnetic transition in spin chain
compound Ca3Co2O
Performance Analysis of Optimal Path Finding Algorithm In Wireless Mesh Network
Wireless Mesh Network has emerged as a key technology for next generation wireless networking because of its advantage over other wireless technologies. Wireless Mesh Network has been widely accepted as a replacement for areas of ad-hoc network or MANET. Multi hop wireless mesh technology has become a new paradigm for communication. Wireless Mesh Network is an attractive solution for providing last-mile connectivity. ...
Phase coexistence and associated non-equilibrium dynamics under simultaneously applied magnetic field and pressure
A quantitative estimation of the effect of simultaneously applied external
pressure (P) and magnetic field (H) on the phase coexistence has been presented
for Pr0.5Ca0.5Mn0.975Al0.025O3 and La0.5Ca0.5MnO3, where the ferromagnetic
(FM)-metal and antiferromagnetic (AFM)-insulator phases compete in real space.
We found that the nonequilibrium dynamics across the FM-AFM transition is
primarily dictated by the effect of P and H on the supercooling, superheating
temperatures, and the nucleation and growth rate of the equilibrium phase.
These effects across the transition is also responsible for the relative volume
fraction of the competing phases at low temperature. Importantly in the entire
magnetic field-pressure-temperature range of phase coexistence, the interface
between the two competing phases having different spin and structural order
plays a very important role in controlling the non-equilibrium dynamics
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