Study On Magnetic And Thermodynamic Properties Of Borophene Clusters And Borophene Nanoribbons

Recently,borophene clusters and borophene nanoribbons have been successfully synthesized in experiment with unique physical and chemical properties.It is another novel two-dimensional material since graphene.Borophene clusters has potential applications in the fields of magnetism,electronics,biology,energy science and so on.Therefore,research for magnetic mechanism of borophene clusters has great significance to improve relevant theories and experiments.In this paper,we use Monte Carlo simulation method to study borophene clusters and borophene nanoribbons with B₃₆ unit.The effects of the exchange coupling and anisotropy on step effect,magnetization,magnetic susceptibility,blocking temperature,internal energy and specific heat of the system have been studied in detail.Research results for borophene clusters with B₃₆ units have been shown as follow.In low temperature,the curves of the total average magnetization for the system have appeared multi-step phenomenon with various exchange coupling and anisotropy in the magnetic field.It is caused by the flip between the high and low spin states of the sublattice.The magnetization curves with the change of temperature have shownd two types.One is that the magnetization decreases with increasing temperature.The second is that the magnetization in the low temperature area shows firstly a maximum,then decreases rapidly with increasing temperature.The magnetic susceptibility curve have shown peak which corresponds to temperature named as the blocking temperature.It increases with increasing antiferromagnetic exchange coupling|J|and ferromagnetic exchange J₂?J₃?,while decreases with increasing anisotropy|D₁|?|D₄|?.Therefore,the blocking temperature can be regulated by intervening exchange couplings and anisotropies.There is also an obvious peak on the specific heat curve,corresponding to temperature increases with increasing exchange coupling|J|?J₂,J₃?and decreases with increasing anisotropy|D₁|?|D₄|?.Research results for borophene nanoribbons with B₃₆ units have been shown as follow.In low temperature,the number of steps on the magnetization curves decrease with increasing|J|?J₃?,and increase with increasing value of anisotropy.Magnetization curve decreases with increasing temperature.In addition,the curves have appeared a new type which occur maximum phenomenon within certain parameters.Two different saturated magnetic moments have appear in the system for different value of anisotropy.The temperature corresponding to the peak value of magnetic susceptibility curve varies with the changing exchange coupling and anisotropy.The effect of the anisotropy D₂,D₃ and D₄ on internal energy of the system in whole temperature area have been studied.An obvious peak shows on the specific heat curve,and the temperature corresponding to the peak changes with various parameters.