To electrically control magnetic properties of material is promising toward spintronic applications, where the investigation of carrier doping effects on antiferromagnetic (AFM) materials remains challenging due to their zero net magnetization. In this work, the authors find electron doping dependent variation of magnetic orders of a 2D AFM insulator NiPS 3 , where doping concentration is tuned by intercalating various organic cations into the van der Waals gaps of NiPS 3 without introduction of defects and impurity phases. The doped NiPS 3 shows an AFM-ferrimagnetic (FIM) transition at a doping level of 0.2-0.5 electrons/cell and a FIM-AFM transition at a doping level of ≥0.6 electrons/cell. The authors propose that the found phenomenon is due to competition between Stoner exchange dominated inter-chain ferromagnetic order and super-exchange dominated AFM order at different doping level. The studies provide a viable way to exploit correlation between electronic structures and magnetic properties of 2D magnetic materials for realization of magnetoelectric effect.

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Thermal management has become a crucial issue for the rapid development of electronic devices, and thermal interface materials (TIMs) play an important role in improving heat dissipation. Recently, carbon−based TIMs, including graphene, reduced graphene oxide, and carbon nanotubes (CNTs) with high thermal conductivity, have attracted great attention. In this work, we provide graphene−carbon nanotube composite films with improved electrical and thermal conductivities. The composite films were prepared from mixed graphene oxide (GO) and CNT solutions and then were thermally reduced at a temperature greater than 2000 K to form a reduced graphene oxide (rGO)/CNT composite film. The added CNTs connect adjacent graphene layers, increase the interlayer interaction, and block the interlayer slipping of graphene layers, thereby improving the electrical conductivity, through−plane thermal conductivity, and mechanical properties of the rGO/CNT composite film at an appropriate CNT concentration. The rGO/CNT(4:1) composite film has the most desired properties with an electrical conductivity of ~2827 S/cm and an in−plane thermal conductivity of ~627 W/(m·K). The produced rGO/CNT composite film as a TIM will significantly improve the heat dissipation capability and has potential applications in thermal management of electronics.