Frequency dispersion of hysteresis in core/shell magnetic nanoparticle: Monte Carlo simulation

2008 ◽  
Vol 103 (7) ◽  
pp. 07B103 ◽  
Author(s):  
M. H. Wu ◽  
S. Dong ◽  
J.-M. Liu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Magnetic Nanoparticle ◽  
Frequency Dispersion ◽  
Core Shell

The ferroelectric properties of Cd2Nb2O7: a Monte Carlo simulation study

2011 ◽  
Vol 44 (3) ◽  
pp. 585-594 ◽  
Author(s):  
T. Malcherek
Keyword(s):  
Phase Transition ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Transition Temperature ◽  
Soft Mode ◽  
Ferroelectric Properties ◽  
Low Frequency ◽  
Frequency Dispersion ◽  
Monte Carlo Simulation Study ◽  
First Order Phase Transition

The order–disorder contributions to the ferroelectric properties of Cd2Nb2O7(CNO) have been studied by Monte Carlo simulation of a 12-state modified Potts model on the pyrochlore lattice. Spin configurations obtained by these simulations are mapped to local Nb displacements. Secondary Cd displacements normal to the Nb displacement directions are considered as well. The model correctly reproduces diffuse scattering experimentally observed in CNO. A first-order phase transition is observed forkTp/J= 0.3891 (kis the Boltzmann constant,Tpis the model phase transition temperature andJis the interaction energy). To further adapt the model to the properties of CNO, coupling of local Nb displacements to theT2usoft mode is simulatedviathe addition of an appropriate field term in the model Hamiltonian. The critical temperatureTcof the soft mode is scaled tokTc/J= 0.3704. Similarities to experimental observations,i.e.the occurrence of stable domains with {100} boundaries, as well as spontaneous polarization along the cubic 〈100〉 and 〈110〉 directions, indicate thatTpcan be associated with the transition temperatureT1= 205 K in CNO. Frequency dispersion of the dielectric permittivity of CNO can be attributed to the low-frequency switching of correlated chains of Nb displacement that remain partially disordered in the temperature range between 195 and ∼100 K.

Magnetic Properties of the Cylindrical Ising Nanowire: A Monte Carlo Simulation Study

SPIN ◽  
2017 ◽  
Vol 07 (04) ◽  
pp. 1750011 ◽  
Author(s):  
A. Jabar ◽  
R. Masrour ◽  
M. Hamedoun ◽  
A. Benyoussef
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Crystal Field ◽  
Remanent Magnetization ◽  
Hysteresis Loops ◽  
Core Shell ◽  
Monte Carlo Simulation Study ◽  
The Core ◽  
Magnetic Nanowire

A cylindrical ferrimagnetic magnetic nanowire system of core and shell layers has been investigated using Monte Carlo simulation. Critical temperature is obtained for different values of exchange couplings at the core–shell interface, at shell–shell and core–core. The total magnetization has been the determinate for different values of crystal field. Hysteresis loop, coercive field and remanent magnetization of a core and shell layers are obtained using the Monte Carlo simulation. A number of characteristic behaviors are found, such as the occurrence of single and triple hysteresis loops for appropriate values of crystal field, temperatures values and exchange interaction values.

Surface faceting and compositional evolution of Pd@Au core–shell nanocrystals during in situ annealing

2019 ◽  
Vol 21 (6) ◽  
pp. 3134-3139 ◽  
Author(s):  
Zhemin Wu ◽  
Min Tang ◽  
Xiaoyan Li ◽  
Sai Luo ◽  
Wentao Yuan ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Transformation Process ◽  
Au Nanoparticle ◽  
Core Shell ◽  
Compositional Evolution

A step-wise transformation process of a Pd@Au nanoparticle both structurally and compositionally was observed. Monte Carlo simulation was used to explain the results.

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