Dynamics of Self-Induced Quantum Vortices in Ferromagnetic Superconductor RuSr2YCU2O8

在RuRu和CuMKR研究的基础上，我们给出了铜酸盐超导体RuSr2YCu2OH(RuY1212)中超导和铁磁共存的证据。零场Ru-核磁共振信号的射频场显著增强的观测结果表明，在居里温度T_M=150K以下的有序RuO_2面上存在铁磁(FM)分量。在超导起始温度T_c(起始)=45K以下，观察到有序RuO_2面内和CuO_2面内的核自旋晶格弛豫速率1/T_i显著降低，表明超导能隙在微观尺度上与RuO_2面上的FM分量共存。此外，从观察到^&lt；10&gt；在T_c=108K的五层化合物HgBa2Ca4Cu5Oy(HgBa2Ca4Cu5Oy)中，超导和反铁磁性共存。铜核磁共振研究表明，最佳掺杂的OP在T_c=108K时发生了超导(SC)相变，而三个欠掺杂IP在T_x~60K以下发生了反铁磁(AF)相变，其铜矩为~0.3-0.4μ_&lt；K^+&gT；在IP处的AF自旋极化在SC OP处诱导了内场效应。观察到的金属行为表明，Sc和Af有序参数可能共存于单一的CuO_2平面中。

Frora Ru- and Cu MKR studies, we have presented evidence for coexistence of superconductivity and ferroraagnetism in a cuprate superconductor RuSr_2YCu_2O_H (RuY1212). The observation of a large enhancement of a radio-frequency field for the Ru-NMR signal at zero field reveals the existence of a ferromagnetic (FM) component in the ordered RuO_2 plane below a Curie temperature of T_M = 150 K. Just best below the onset temperature of superconductivity Tc(onset)= 45 K, a remarkable decrease of the nuclear spin-lattice relaxation rate 1/T_I was observed within the ordered RuO_2 plane as well as the CuO_2 plane revealing that the superconducting gap coexists with the FM component in the RuO_2 plane on a microscopic scale. In addition, from the the observation of a sharp pesk in ^<10>(L/T_I) at Tc(zero) 〜23 K where the resistivity becomes zero, we suggest that the motion of self-induced vortices originating from fluctuations of the FM component induces the resistivity between T c(onset) and T c(zero) in RuY1212.We alos have reported a coexistence of superconductivity and antiferromagnetism in five-layered compound HgBa_2Ca_4Cu_5O_y (Hg-1245) with T_c=108 K, which is composed of two types of CuO_2 planes in a unit cell, Three inner planes (IP) and twe outer planes (OP). The Cu-NMR study study has revealed that the optimally-doped OP undergoes a supercondcting (SC) transition at T_c=108 K, whereas the three underdoped IP's do an antiferromagnetic (AF) transition below T_x〜60 K with the Cu moments of 〜0.3-0.4μ_<K^+> The AF spin polarization at the IP is found to induce an internal fied at the SC OP. The observed metallic behavior at the IP gives the possibility that SC and AF order parameter coexist in a single CuO_2 plane.