Local transport properties of PrFeAsO0.7 using FIB micro-fabrication technique

Abstract

To evaluate the anisotropy of single crystals with a size of several tens of micrometers, we develop a technique for measuring the local transport properties along both the ab-plane and the c-axis using microsize devices fabricated by a focused ion beam process. We applied this technique to identify the resistivity anisotropy (γρ=ρc/ρab) of the iron-pnictide superconductor PrFeAsO0.7 synthesized under high-pressure. The obtained value of γρ∼120 at 50K indicates the presence of strong anisotropy, which is comparable to the anisotropy measured by other methods. The weak temperature dependence detected for the normalized resistivity along the c-axis (less than 10% difference at 280K and 50K) suggests a peculiar interlayer transport mechanism for PrFeAsO0.7.