Direct measurements of the penetration depth in a superconducting film using magnetic force microscopy

TL;DR

This paper introduces a magnetic force microscopy technique to locally measure the penetration depth in a superconducting Nb film, providing a new method that aligns well with bulk measurement results.

Contribution

The authors developed a quantitative MFM-based method for measuring the penetration depth in superconducting films, enabling local and precise characterization.

Findings

MFM measurements of penetration depth agree with bulk magnetization results

The method allows for local, non-destructive measurements

Quantitative extraction from single-parameter fits

Abstract

We report the local measurements of the magnetic penetration depth $\lambda$ in a superconducting Nb film using magnetic force microscopy (MFM). We developed a method for quantitative extraction of the penetration depth from single-parameter simultaneous fits to the lateral and height profiles of the MFM signal, and demonstrate that the obtained value is in excellent agreement with that obtained from the bulk magnetization measurements.