Abstract The clear proof of superconductivity in transition-metal diborides was rarely reported. In the current work, the recently developed particle swarm optimization structural search method was utilized to propose three ZrB2 structures, namely, I41/amd-ZrB2, P42/mmc-ZrB2, and P4/nmm-ZrB2. The structural stability of the three novel ZrB2 phases was confirmed on the basis of elastic constant and phonon dispersion calculations. At ambient pressure, the mechanical properties of the I41/amd-ZrB2 and P42/mmc-ZrB2 phases are comparable to those of AlB2–ZrB2. Electron–phonon coupling (EPC) calculations revealed that the P4/nmm-ZrB2 phase is predicted to be a potential high-Tc superconductor with a calculated Tc of 12.7 K at 20 GPa. Moreover, significant pressure-induced EPC enhancement can also be found in the P4/nmm-ZrB2 phase. The maximum EPC constant λ and Tc under 600 GPa are 1.05 and 34.4 K, respectively.

中文翻译：

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ZrB2 多晶型物在压力下的潜在高温超导性

摘要 过渡金属二硼化物超导性的明确证据鲜有报道。在目前的工作中，利用最近开发的粒子群优化结构搜索方法提出了三种 ZrB2 结构，即 I41/amd-ZrB2、P42/mmc-ZrB2 和 P4/nmm-ZrB2。三种新型 ZrB2 相的结构稳定性在弹性常数和声子色散计算的基础上得到证实。在环境压力下，I41/amd-ZrB2 和 P42/mmc-ZrB2 相的机械性能与 AlB2-ZrB2 相媲美。电子-声子耦合 (EPC) 计算表明，P4/nmm-ZrB2 相预计是一种潜在的高 Tc 超导体，在 20 GPa 下计算出的 Tc 为 12.7 K。此外，在 P4/nmm-ZrB2 相中也可以发现显着的压力诱导的 EPC 增强。