Rise and fall of defect induced ferromagnetism in SiC single crystals

TL;DR

This study investigates how defect-induced ferromagnetism in 6H-SiC single crystals varies with structural disorder, revealing a peak in ferromagnetism at intermediate disorder levels before it diminishes with increased damage.

Contribution

It demonstrates the relationship between defect density, structural disorder, and ferromagnetic properties in SiC crystals, highlighting the non-monotonic behavior of magnetism with disorder.

Findings

Ferromagnetism peaks at intermediate disorder levels.

Increased disorder eventually causes lattice amorphization.

Magnetization nearly vanishes near full amorphization.

Abstract

6H-SiC (silicon carbide) single crystals containing VSi-VC divacancies are investigated with respect to magnetic and structural properties. We found that an initial increase of structural disorder leads to pronounced ferromagnetic properties at room temperature. Further introduction of disorder lowers the saturation magnetization and is accompanied with the onset of lattice amorphization. Close to the threshold of full amorphization, also divacancy clusters are formed and the saturation magnetization nearly drops to zero.