The study of spin Glass state in Diluted Magnetic materials and semiconductors using monte carlo method and Theoretical Analysis
| dc.contributor.author | Dulla, Habte | |
| dc.date.accessioned | 2018-06-26T13:07:39Z | |
| dc.date.accessioned | 2023-11-09T11:23:36Z | |
| dc.date.available | 2018-06-26T13:07:39Z | |
| dc.date.available | 2023-11-09T11:23:36Z | |
| dc.date.issued | 2013-03 | |
| dc.description.abstract | Spin glass system is a complex disordered system with a number of local minima separated by entropic barriers. Therefore, Parallel tempering Monte Carlo simulation was used in order to get fast thermalisation (to minimize the relaxation time). Distance dependent interaction coupling in 2D is studied in order to show how a spin glass phase transition occurs when couplings between far away spins are permitted by considering Edwards-Anderson Ising spin glass model. The interaction coupling is a quenched random variable whose probability of being non-zero decays with distance between two spin sites rij = |i−j|mod(L/2). The interaction coupling is random and its probability distribution is decaying with the distance between the spins (p(Jij) / r− ). The model is studied by changing among three different regimes ( > 2D, 4/3D < < 2D, < 4/3D) . A phase transition temperature for = 2, 3, 4 is obtained. In the present work, the possibility of existence of spin glass phase using classical Heisenberg model with Edwards-Anderson type of interactions has been explored employing Monte Carlo simulation of Binder parameter (g (L, T)). Previous experimental studies show that there is finite temperature phase transition but this study indicates that there is no finite temperature phase transition in 3D Heisenberg vector spin glass model. In the dissertation we also explore magnetic properties especially spin glass state, antiferromagnetic state and paramagnetic state of diluted magnetic semiconductors (A1−xMnxA0(A = Zn,Cd and A0 = S, Te, Se)) at critical region using classical Heisenberg spin model with high temperature series expansion extrapolated with vii pad´e approximants. The critical exponents associated with magnetic susceptibility ( ' 1.38 ± 0.1) and correlation function ( ' 0.8 ± o.1) were also obtained | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/3737 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | The study of spin Glass state | en_US |
| dc.title | The study of spin Glass state in Diluted Magnetic materials and semiconductors using monte carlo method and Theoretical Analysis | en_US |
| dc.type | Thesis | en_US |