Unveiling Photoluminescence Signatures of Magneto-Optical Coupling in Layered Hybrid Manganese Chloride Perovskites

TL;DR

This study investigates how magnetic interactions influence photoluminescence in layered hybrid manganese chloride perovskites, revealing complex coupling behaviors that vary with lattice stiffness and temperature, advancing understanding for magneto-optical applications.

Contribution

It provides new insights into the magneto-optical coupling mechanisms in Mn-based HOIPs, highlighting the effects of lattice rigidity and magnetic interactions above the Ne9el temperature.

Findings

Magnetic interactions emerge above the Ne9el temperature.

Lattice stiffness influences the strength of magneto-optical effects.

Different organic cations lead to distinct magnetic and optical behaviors.

Abstract

Understanding the interplay between magnetic ordering and light emission is crucial for developing magneto-optical technologies. However, this phenomenon is poorly understood since observations of this coupling vary significantly across materials. In this context, hybrid organic-inorganic metal halide perovskites (HOIPs) that incorporate Mn2+ ions are a chemically and structurally tunable platform for exploring this phenomenon, since they exhibit magnetic ordering and photoluminescence (PL) emission. Here, we study two antiferromagnetic Mn-based HOIPs with different organic cations that result in distinct lattice stiffness, Mn2+-Mn2+ distance and octahedral distortion. Temperature-dependent PL excitation spectroscopy reveals changes in crystal field splitting energy and Racah parameters well above the N\'eel temperature (TN), indicating the emergence of Mn2+-Mn2+ magnetic interactions prior to reach long-range magnetic ordering. These variations align with the observed changes in temperature-PL evolution. The compound with a more rigid lattice shows stronger changes closer to TN, suggesting combined effects of magnetic polarons and spin-canting. In contrast, magnetic polaron-induced magnetic modifications prevail in the HOIP with a softer lattice. These results reveal the complexity of the magneto-optical coupling in Mn-based HOIPs and provide new insights into this field extensible to other 2D materials that exhibit this phenomenon with potential for advanced magneto-optical applications.