Doping and Irradiation Controlled Vortex Pinning Behavior in BaFe2(As1-xPx)2 Single Crystals

TL;DR

This study investigates how doping and proton irradiation influence vortex pinning in BaFe2(As1-xPx)2 single crystals, revealing transformations in magnetic behavior and the ability to tune vortex dynamics.

Contribution

It demonstrates how doping levels and proton irradiation can systematically modify vortex pinning and magnetic properties in BaFe2(As1-xPx)2 crystals.

Findings

Transition from fishtail to peak effect in magnetization hysteresis.

Strong point pinning dominates at low fields, weak collective pinning at high fields.

Proton irradiation effectively tunes vortex pinning behavior.

Abstract

We report on the systematic evolution of vortex pinning behavior in isovalent doped single crystals of BaFe2(As1-xPx)2. Proceeding from optimal doped to ovedoped samples, we find a clear transfor- mation of the magnetization hysteresis from a fishtail behavior to a distinct peak effect followed by a reversible magnetization and Bean Livingston surface barriers. Strong point pinning dominates the vortex behavior at low fields whereas weak collective pinning determines the behavior at higher fields. In addition to doping effects, we show that particle irradiation by energetic protons can tune vortex pinning in these materials.