In the recent research of material science, as a kind of soft magnetic material, molecular magnet has become a new branch of science, which has been studied by many chemists, physicists and biologists. Compared with traditional magnetic materials, molecular magnet has the advantages of small size, low density, structural diversity and easy-to-composite molding process, these advantages make it likely to be spacecraft, microwave absorption of stealth, electromagnetic shielding and information storage material.Having adopted the Monte Carlo Simulation Method, this paper has researched the various magnetic features of the molecular magnets [ Mn ( N 3 ) 2 ( Etpyz )( H 2O )]n, [ Mn ( N 3 ) 2 (C lpyz ) 2]n, [ Mn ( N 3 ) 2 ( Ipyz ) 2]n and the photomagnetic effect of quantum dot .Firstly, we have studied the molecular magnets [ Mn ( N 3 ) 2 ( Etpyz )( H 2O )]n and the relationship of susceptibility changing with the temperature, given the Lande factors and exchange coupling constant which are consistent with experimental results. Particularly, we have found a method of studying the molecular magnets in a more suitable low temperature.Secondly, we have studied the magnetic properties of the molecular magnets [ Mn ( N 3 ) 2 (C lpyz ) 2]n and [ Mn ( N 3 ) 2 ( Ipyz ) 2]n. It is the first time to give the Lande factors and the exchange coupling constant in theory. Also, we have found that their spin configuration is the ferromagnetic distribution in the horizontal direction and the anti-ferromagnetic distribution in the vertical direction at low temperatures. This conclusion has certain guiding significance on the experimental study of magnetic properties of molecular magnets.Finally, we have studied the magnetic features of the photomagnetic effect of quantum dot. The results show that the quantum dot changes the spin size, and the direction is in line under the influence of the photomagnetic effect, so that the magnetizing strength increased. The result also found that the spin configuration tends to be vertical at the low temperature, and the inhibition of the magnetic field to the photomagnetic effect appears of ladder-like distribution. This conclusion provides certain theory basis on the correlation experimental study.Depending on all above studies, we give the magnetic characteristics of the molecular magnets [ Mn ( N 3 ) 2 ( Etpyz )( H 2O )]n, [ Mn ( N 3 ) 2 (C lpyz ) 2]n, [ Mn ( N 3 ) 2 ( Ipyz ) 2]n and the photomagnetic effect of quantum dot, which provides a useful reference to further study the molecular magnets and the photomagnetic effect of quantum dot in research. |