Recently, phenyl molecules have been reported to exhibit Meissner effect mainly from magnetization measurements. Realizing zero-resistivity state in these materials seems a challenge due to many practical difficulties but is required to characterize the existence of superconductivity. By choosing potassium-doped tris(2-methylphenyl)bismuthine as an example, we perform temperature-dependent magnetic susceptibility and resistivity measurements at different magnetic fields and pressures. The solid evidence for supporting superconductivity is achieved from the obtained Meissner effect and zero resistivity with the critical temperature ($T_c$) of 3.6 K at atmosphere pressure. Upon compression, we observe the gradual evolution of superconductivity from its initial phase with a parabolic behavior of $T_{c}$ to the second one with almost constant value of $T_{c}$ of 7 K. The 7 K phase seems a common feature for these newly discovered phenyl-based superconductors.
Coexistence of superconductivity and antiferromagnetism in single crystals $A_{0.8}Fe_{2-y}Se_2$ (A= K, Rb, Cs, Tl/K and Tl/Rb): evidence from magnetization and resistivity
测量了$A$ Fe $_{2-y}$ Se $_2$（$A$ = KPDMATHABMP，RbPDMATHABMP，$_{0.8}$，$_{0.5}$ $_{0.3}$和$_{0.4}$ $_{0.4}$）单晶在5 ~ 600 K温度范围内的电阻率和磁化率.在低温电阻率和磁化率中观察到了一个急剧的超导转变，磁化率的Meissner体积分数为100%，而在Neel温度（$T_N$）高达500 ~ 540 K（取决于A）时观察到了反铁磁转变。它表明超导性和反铁磁性共存。在略高于$T_{\rm N}$的温度下，由于Fe空位有序化引起的结构转变引起电阻率的急剧增加。在具有如此高的$T_{\rm N}$的反铁磁有序态中出现超导性可能暗示了这种非常规超导体中的新物理。
High field paramagnetic Meissner effect in Mo$_{100-x}$Re$_x$ alloy superconductors
我们对一系列超导Mo $_{100-x}$ Re $_x$合金的磁化强度与温度和磁场的关系进行了实验研究。我们的研究揭示了在这些低温超导体中存在高场顺磁效应。研究结果表明，Mo $_{100-x}$ Re $_x$合金中的HFPME与样品在强磁场中冷却时强、弱磁通钉扎中心的不均匀分布以及由此产生的磁通压缩有关。对这些合金在不同恒定磁场中的电阻率和热容随温度的变化关系进行了研究。我们将我们的研究结果与文献中报道的低$T_C$和高$T_C$超导体的研究结果进行了比较。
