Publication Type
Journal
Journal Name
Physical Review B
Publication Date
Page Number
094446
Volume
100
Issue
9
Abstract
A series of Sr(Co1−xNix)2As2 single crystals was synthesized, allowing a comprehensive phase diagram with respect to field, temperature, and chemical substitution to be established. Our neutron diffraction experiments revealed a helimagnetic order with magnetic moments ferromagnetically aligned in the ab plane and a helimagnetic wave vector of q=(0,0,0.56) for x=0.1. The combination of neutron diffraction and angle-resolved photoemission spectroscopy measurements shows that the tuning of a flat band with dx2−y2 orbital character drives the helimagnetism and indicates the possibility of a quantum order-by-disorder mechanism.
