SYNTHESIS OF Ru_1-xSb_xSr₂(Eu_0.7Ce_0.3)₂Cu₂O_10-δ AND THEIR MAGNETIC AND TRANSPORT PROPERTIES

Abstract

Ru 1-x Sb x Sr 2( Eu 0.7 Ce 0.3)2 Cu 2 O 10-δ systems were prepared by conventional solid state reaction method. The structural analysis was investigated using X-ray diffraction. Electrical resistivity, Hall effect and magnetic susceptibility measurements on Ru :1222 doped with Sb are presented, together with results in the temperature range 5–300 K. Transition temperature decreases from 43 K for x = 0.00 to 20 K for x = 0.06 Sb . This may be due to a distortion of RuO 6 octahedral, which is responsible of the increase in hole localization. The Hall effect anomalous decreases below T magnetic which may be explained within a simple two-band model by a transition from localized to more itinerant behavior in the RuO 2 layer at T magnetic . The behavior of magnetic susceptibility is caused by an antisymmetric exchange coupling of the Dzyaloshinsky–Morya type between neighboring Ru moments.

Transport, thermal and magnetic properties of Ru1−xSbxSr2(Gd0.7Ce0.3)2Cu2O10−d

“…7 The Sb +3 ion substitutes for Ru +5 in solid solution has a dramatic effect on the transport and magnetic properties in agreement with Refs. [4,5,7].…”

“…Polycrystalline samples with a nominal composition Ru 1Àx Sb x Sr 2 (Gd 0.7 Ce 0.3 ) 2 Cu 2 O 10Àd (where 0pxp0.06) were synthesized by a solid-state reaction method presented in previous works [5]. The X-ray powder diffraction patterns were taken using Cu K a radiation.…”

“…The discovery of the coexistence of magnetic order (FM) at T m ¼ 60-180 K and superconductivity (SC) below T c ¼ 30-50 K in the tetragonal rutheno-cuprate layered Ru: 1212, Ru:1222 and, recently, Ru:1232 [1][2][3][4][5][6] raises the question how these two antagonistic states of matter can accommodate each other?. The physical nature of superconducting and ferromagnetic states is far from being understood.…”

Superconductivty and magnetic properties of <TEX>$(Ru_{1-x}Nb_x)Sr_2(Sm_{1.4}Ce_{0.6})Cu_2O_z$</TEX>

“…이들 자성 초전도체의 구성은 일반적으로 RuSr2(R2-yCey)Cu2O10(Ru-1222) 및 RuSr2RCu2O10(Ru-1212) 로 나타낼 수 있으며, R 은 희토류 원소로서 Sm, Eu 및 Gd 의 경우만 상압에서 단 일상이 형성됨이 알려져 왔다 [4]. 특히 Ru-1222 계는 Ru-1212 계에 비해 강자성 특성이 크게 관측되어 [5] 그 원인을 파악하기 위해 많은 치환연구가 수행되어 왔 으며, (Ru1-xMx)Sr2(R2-yCey)Cu2O10((Ru,M)-1222) 조성에 대한 연구에서 M = Fe [6], Co [7], Nb [8,9], Mo [10], Sn [11], Sb [12] …”