The current research focuses on analyzing the magnetic and magnetocaloric properties of REH2(RE=Gd,Tb,Dy) in a CaF2-like face-centered cubic system. Through the application of first-principles ...calculations and Monte Carlo simulations, the following physical parameters are determined: Adiabatic temperature change, isothermal entropy change, and relative cooling power (RCP). The magnetic moments of Gadolinium, Terbium, and Dysprosium calculated by the PWSCF method are 6.76μB, 5.74μB, and 4.65μB respectively, aligning well with experimental results. The compounds underwent a second-order phase transition from antiferromagnetic to paramagnetic at TN=21.7K, 17.6K, and 4.3K respectively for GdH2, TbH2, and DyH2. The isothermal entropy change (−ΔSMmax) reached a maximum value of −11.75J/kg.K, −12.47J/kg.K, and −12.87J/kg.K for GdH2, TbH2, and DyH2 under a magnetic field of 5T. We found also that the hydrogenation of rare earth reduces its magnetic performance while but it enhances its thermodynamic and mechanical stability.
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•The thermodynamic and mechanical stability of REH2(RE=Gd,Tb,Dy) compounds are investigated.•The REH2 compounds are metals with an antiferromagnetic state.•The magnetocaloric property values of REH2 compounds indicate that they are potential for low-temperature magnetic refrigeration applications.•Comparing the properties of Gd with REH2 compounds reveals the role of hydrogen in these materials.
2D materials beyond graphene and in particular 2D semiconductors have raised interest due to their unprecedented electronic properties, such as high carrier mobility or tunable bandgap. Blue ...phosphorene is an allotrope of black phosphorene that resembles graphene as it presents a honeycomb structure. However, it is known to have semiconductor character and the crucial point is to determine whether this hexagonal phase of phosphorene presents Dirac fermions as in graphene. Here, the first compelling experimental evidence of Dirac fermions in blue phosphorene layer grown on Cu(111) surface is presented. The results highlight the formation of a highly ordered blue phosphorene sheet with a clear Dirac cone at the high symmetry points of the Brillouin Zone. The charge carriers behave as massless relativistic particles. Therefore, all the expectations held for graphene, such as high‐speed electronic devices based on ballistic transport at room temperature, may also be applied to blue phosphorene.
Blue phosphorene is a new emerging 2D semiconducting material with potential applications. Herein, an evidence of the existence of Dirac fermions in blue phosphorene grown on Cu(111) substrate, similar to graphene, is presented. Therefore, all the expectations held for graphene, such as high‐speed electronic devices based on ballistic transport at room temperature, may also be applied to blue phosphorene.
