论文标题
硼含量和碳基材料的超导临界温度
Boron Content and the Superconducting Critical Temperature of Carbon-Based Materials
论文作者
论文摘要
在本文中，我们介绍了硝酸硼 - 碳（BN-C）和硼碳化碳（B4C-C）颗粒混合物的磁化特性的结果。在冷却过程中冷却和在变暖期间的场冷却的场冷却的温度依赖性磁化显示出一种热滞后，始终在从抗磁磁性马脑岩到铁磁磁性奥斯丁阶段的metagnetic相跃迁周围看到。低温磁化具有向上的转弯，可以归因于超paragnetism，diamagnetic屏蔽和被困的通量特征，这些特征是高温超导材料。减去磁磁背景后，依赖场的磁化环M（B）是铁磁样的，对于BN-C而言，比B4C-C混合物更重要。此外，磁化环显示了颗粒超导性的扭结特征。具有37.5 wt％b的B4C-C混合物的不可逆性温度为TC = 76K。将我们的数据与B掺杂钻石和Q-碳的先前结果结合在一起，我们发现TC随B浓度呈线性增加。
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.
