Neutron scattering measurements have demonstrated that the heavily Cu doped NaFe1-xCuxAs compound behaves like a Mott insulator exhibiting both real-space Fe-Cu stripes and antiferromagnetism below a Neél temperature for xâ‰0.5. We have investigated the evolution of structural and magnetic ordering using Na23 and As75 NMR for single crystals (x = 0.39 and 0.48), confirming antiferromagnetism in the form of magnetic stripes. We show that end-chain defects in these stripes are the principal source of magnetic disorder and are responsible for cluster spin-glass transitions in both compounds, in the latter case coexistent with antiferromagnetism. Aided by our numerical simulation of the As75 spectra, we show that a staggered magnetization at the Fe sites is induced by nonmagnetic Cu dopants.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics