2020/12/11 by Nadina Gheorghiu, Gheorghiu, Nadina, Charles R. Ebbing +3
Materials Science · #Boron and Carbon Nanomaterials Research #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Graphene research and applications #Superconductivity (cond-mat.supr-con) #Thermal properties of materials
paper · pdf · doi:10.48550/arxiv.2012.06624
openalex publication_date 2020/12/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we present results on magnetization properties of boron\nnitride-carbon (BN-C) and boron carbide-carbon (B4C-C) granular mixtures. The\ntemperature-dependent magnetization for field-cooled during cooling and\nfield-cooled during warming shows a kind of thermal hysteresis that is always\nseen around a metamagnetic phase transition from an antiferromagnetic\nmartensite to a ferromagnetic austenite phase. The low-temperature\nmagnetization has an upward turn that can be attributed to superparamagnetism,\ndiamagnetic shielding, and trapped flux characteristic to high-temperature\nsuperconducting materials. After subtracting the diamagnetic background, the\nfield-dependent magnetization loops M(B) are ferromagnetic-like, more\nsignificant for the BN-C than for the B4C-C mixture. In addition, the\nmagnetization loops show the kink feature characteristic to granular\nsuperconductivity. The irreversibility temperature for a B4C-C mixture having\n37.5 wt% B is Tc = 76 K. Combining our data with previous results on B-doped\ndiamond and Q-carbon, we find that Tc increases linearly with the B\nconcentration.\n