Boron Content and the Superconducting Critical Temperature of Carbon-Based Materials
Abstract
In this paper, we present results on magnetization properties of boron nitride-carbon (BN-C) and boron carbide-carbon (B4C-C) granular mixtures. The temperature-dependent magnetization for field-cooled during cooling and field-cooled during warming shows a kind of thermal hysteresis that is always seen around a metamagnetic phase transition from an antiferromagnetic martensite to a ferromagnetic austenite phase. The low-temperature magnetization has an upward turn that can be attributed to superparamagnetism, diamagnetic shielding, and trapped flux characteristic to high-temperature superconducting materials. After subtracting the diamagnetic background, the field-dependent magnetization loops M(B) are ferromagnetic-like, more significant for the BN-C than for the B4C-C mixture. In addition, the magnetization loops show the kink feature characteristic to granular superconductivity. The irreversibility temperature for a B4C-C mixture having 37.5 wt% B is Tc = 76 K. Combining our data with previous results on B-doped diamond and Q-carbon, we find that Tc increases linearly with the B concentration.
Keywords
Cite
@article{arxiv.2012.06624,
title = {Boron Content and the Superconducting Critical Temperature of Carbon-Based Materials},
author = {Nadina Gheorghiu and Charles R. Ebbing and Timothy J. Haugan},
journal= {arXiv preprint arXiv:2012.06624},
year = {2020}
}
Comments
5 pages, 10 figures