Short-range cluster spin glass near optimal superconductivity in BaFe2−xNixAs2

In Chap. 4, we noted that the emergent incommensurate (IC) short-range antiferromagnetic (AF) order near optimal superconductivity of Ba(Fe\(_{1-x}\)Co\(_{x}\))\(_2\)As\(_{2}\) heavily modifies the electronic properties of this doping region and preempts the purported quantum critical point (QCP). Therefore, it is of particular interest to investigate the nature of the IC AF order.