Superconductivity in Y₂C₃with mediumT_c

Abstract

Recently, we have reported a relatively high-T c superconductivity in Y 2 C 3 at 18 K whose T c could be changed by synthesis conditions from 10 to 18 K [G. Amano, S. Akutagawa, T. Muranaka, Y. Zenitani, J. Akimitsu, Superconductivity at 18 K in yttrium sesquicarbide system, Y 2 C 3 J. Phys. Soc. Jpn. 73 (2004) 530.]. We synthesized a high-purity sample of the medium-T c phase in Y 2 C 3 and examined its physical properties in detail. From a specific heat measurement, DC(T c )/gT c value is calculated to be 6.50 and the superconducting gap is estimated to be 2D/k B T c Z5.40, indicating that the superconductivity in Y 2 C 3 can be described by an s-wave strong coupling regime. q

Superconductivity in Carbide Compounds

“…However, the mechanism of superconductivity in Y 2 C 3 has not been well understood because of the diffi culty involved in synthesizing stable, single-phase Y 2 C 3 in air. We established a technique for synthesizing high-purity samples, and prepared samples having various T c 's to investigate the mechanism of the variation of T c in this system [14,15]. As shown in Figure 3, the magnetic susceptibility of Y 2 C 3 decreased signifi cantly at each T c and the superconducting volume fraction of each T c sample at lowest temperature in susceptibility measurements (1.8 K) was estimated to be approximately 40% in the fi eld cooling process.…”

Novel High-Pressure Yttrium Carbide γ−Y4C5 Containing [ Aslandukovа1, Aslandukov2, Yuan3 et al. 2021Phys. Rev. Lett.

“…Whereas the crystal structure of α-Y 4 C 5 was solved and refined [space group Pbam (#55), a ¼ 6.5735ð9Þ, b ¼ 11.918ð1Þ, c ¼ 3.6692ð5Þ Å] at ambient conditions [23], the structure of β-Y 4 C 5 remains unknown. Under high pressure, only Y 2 C 3 has been investigated [24][25][26]. Here, we report on the synthesis and characterization of a new high-pressure modification of yttrium carbide, γ-Y 4 C 5 , with novel structure and very unusual crystal chemistry.…”

Strong antisymmetric spin–orbit coupling and superconducting properties: the case of noncentrosymmetric LaPtSi

“…Y 2 C 3 may also be in conflict, although the two results reported so far in this compound are contrasting. Penetration depth indicates line nodes [43], whereas heat capacity suggests an isotropic energy gap [42].…”