Specific Resistance of Pd/Ir Interfaces

TL;DR

This study measures and calculates the specific electrical resistance at Pd/Ir interfaces, comparing experimental data with theoretical models to understand interface properties in multilayer structures.

Contribution

It provides the first precise measurement of Pd/Ir interface resistance and compares it with detailed theoretical calculations including f-orbitals.

Findings

Experimental interface resistance: 1.02 +/- 0.06 fOhmm^2.

Theoretical calculations with f-orbitals agree with experimental values.

Interface resistance varies with alloy composition and modeling assumptions.

Abstract

From measurements of the current-perpendicular-to-plane (CPP) total specific resistance (AR = area times resistance) of sputtered Pd/Ir multilayers, we derive the interface specific resistance, 2AR(Pd/Ir) = 1.02 +/- 0.06 fOhmm^2, for this metal pair with closely similar lattice parameters. Assuming a single fcc crystal structure with the average lattice parameter, no-free-parameter calculations, including only spd orbitals, give for perfect interfaces, 2AR(Pd/Ir)(Perf) = 1.21 +/-0.1 fOhmm^2, and for interfaces composed of two monolayers of a random 50%-50% alloy, 2AR(Pd/Ir)(50/50) = 1.22 +/- 0.1 fOhmm^2. Within mutual uncertainties, these values fall just outside the range of the experimental value. Updating to add f-orbitals gives 2AR(Pd/Ir)(Perf) = 1.10 +/- 0.1 fOhmm^2 and 2AR(Pd/Ir)(50-50) = 1.13 +/- 0.1 fOhmm^2, values now compatible with the experimental one. We also update, with f-orbitals, calculations for other pairs