Selective dopant induced spin flipping and complex ferro–antiferromagnetic interaction in Nd based cuprate francisite

Abstract

A study of Nd based cuprate francisite (NdCufr) is fascinating due to the presence of competing magnetic interactions in this geometrically frustrated layered compound, and Ni doping helps in tailoring these interactions. Here, Ni doped NdCufr is synthesized to compare its magnetic properties with pristine and Co doped NdCufr. Structural (x-ray diffraction, XRD), electronic (x-ray absorption near edge spectroscopy, XANES, and extended x-ray absorption fine structure, EXAFS), and magnetic (temperature dependent magnetization, M–T; field dependent magnetization, M–B) properties are investigated. The XRD, XANES, and EXAFS measurement data show a perfect crystal structure and confirm the merit of doping. A comprehensive comparison for examining the role of Co and Ni in modulation with ferromagnetic–antiferromagnetic interaction strength is presented. A crucial interplay of intra- and interlayer couplings, along with f–d interaction, effectively describes the tuning of Neel temperature (TN) and M–B. Detailed processes of field induced metamagnetic transition around the spin-flip ordering field (BSF), which is equal to that of the critical field (BC) and doping induced ferromagnetism, are addressed considering the relative spin orientations of magnetic elements and energy level splitting schemes, respectively. It is found that the studied compound is magnetically superior to the compared compounds.