Static and dynamic magnetic properties of lightly P-substituted BaFe 2(As 1-xP x) 2 were systematically investigated by 31P NMR. The averaged internal magnetic field at the P site in the zero-temperature limit evaluated from the broadening of NMR spectra in the antiferromagnetic (AFM) phase is gradually suppressed toward x∼0.35 with increasing x, which provides definitive evidence for the existence of an AFM quantum critical point (QCP) at x∼0.35. The location of the AFM QCP is consistent with the previous estimation from temperature dependence of spin dynamics in the normal state, and the superconducting transition temperature T c takes the maximum around the QCP. Our experiments, revealing a signature of a QCP extending up to room temperature, establish BaFe 2(As 1-xP x) 2 as one of the most accessible systems for unraveling the nature of quantum criticality and the relationship between AFM quantum criticality and unconventional superconductivity.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - May 4 2012|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics