Pressure dependence of antiferromagnetic and superconducting phases in U2Rh1-xPtxC2

Article

关键词: FERMI-LIQUID BEHAVIOR;    ELECTRICAL-RESISTIVITY;    METALS;   

DOI  :  10.1103/PhysRevB.102.035124

来源: SCIE

【 摘 要 】

We report temperature (T)- and pressure (P)-dependent resistivity measurements on the isostructural compounds U2Rh1-xPtxC2 (x = 0, 0.5, and 0.9) from which we construct a T -P-x phase diagram. Compounds with x = 0 and x = 0.5 are antiferromagnets below 22.1 and 9.4 K, respectively, and their Ned temperature (T-N) decreases under applied pressure. For x = 0, the critical pressure P-c required to suppress T-N to zero temperature is projected to be about 8.8 GPa, but P-c for x = 0.5 is between 1.6 and 2.1 GPa. At atmospheric pressure, increasing Pt concentration in U2Rh(1-x)PtxC2 tunes magnetic transition temperatures to zero at a critical value of x(c) approximate to 0.7, and, consequently, we surmise the existence of a quantum-phase boundary in the P - x plane at T = 0 K that extends from (P = 0, x = x(c)) to (P-c approximate to 8.8 GPa, x = 0). For x = 0.9, superconductivity appears at T-c = 1.09 K, which decreases at a rate of approximate to -1 K/GPa that is nearly twice that found for U2PtC2 whose T-c is 1.47 K. Together, these results indicate that domes of magnetism and superconductivity formed with T-P-x variations are detached and that the two broken symmetries are independent of each other. Fluctuations in average composition produce rare regions that play an important role in determining physical properties of materials with noninteger x.

【 授权许可】

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