Variable range hopping conduction in LaC2, CeC2, or GdC2 crystals encapsulated carbon nanocages

TLDR: In this paper, an experimental study of electrical transport phenomena in magnetic fields H up to 15 T in pressed samples of three porous systems composed of carbon nanocages in which LaC2, CeC2 or GdC2 crystals are encapsulated is reported.

Abstract: An experimental study of electrical transport phenomena in magnetic fields H up to 15 T in pressed samples of three porous systems composed of carbon nanocages in which LaC2, CeC2, or GdC2 crystals are encapsulated is reported. The exp[(T0/T)1/3] temperature dependence in the zero‐field dc electrical resistance R(0) is found at low temperatures. Below 50, 50, and 35 K for the LaC2, CeC2, and GdC2 system, respectively, transverse magnetoresistance (MR), [R(H)–R(0)]/R(0), is negative. In the weak field region (H<0.15 T), the negative MR is quadratic in H, and becomes linear in the field range 0.15–0.5 T. The linear and negative MR shows T−1.04±0.10 temperature dependence. The temperature dependence of R(0) is described in terms of Mott’s law for two‐dimensional variable range hopping (2D VRH) conduction. The low field magnetotransport features support a predicted quantum interference effect on 2D VRH conduction.