Perovskite materials have emerged as a promising platform for spintronic applications due to their unique spin-related properties. These materials exhibit strong spin-orbit coupling, Rashba splitting, and tunable spin lifetimes, making them suitable for spin-based devices. The ability to incorporate magnetic dopants like manganese (Mn) further enhances their potential for spintronics by introducing magnetic interactions and proximity effects. This article explores the spin-related phenomena in perovskites, focusing on their fundamental mechanisms and implications for spintronic applications.

One of the key features of perovskites in spintronics is the Rashba effect, which arises from strong spin-orbit coupling and structural inversion asymmetry. The Rashba effect leads to momentum-dependent splitting of electronic bands, creating spin-polarized states. In lead halide perovskites, such as MAPbI3, the Rashba splitting energy can reach up to 40 meV, as observed in angle-resolved photoemission spectroscopy studies. This splitting is influenced by the organic cations in the perovskite structure, which break inversion symmetry and enhance spin-orbit interactions. The Rashba effect enables efficient spin manipulation using electric fields, a critical requirement for spintronic devices.

Spin-orbit coupling in perovskites is another crucial factor governing their spintronic properties. The heavy elements in perovskites, such as lead and iodine, contribute to strong spin-orbit interactions, which couple the electron's spin to its orbital motion. This coupling facilitates spin relaxation and dephasing processes, impacting spin lifetimes. For instance, in CsPbBr3, spin-orbit coupling leads to a Dresselhaus-like splitting, complementing the Rashba effect. The interplay between these mechanisms determines the overall spin dynamics in the material. Measurements using time-resolved Kerr rotation have revealed spin lifetimes in the nanosecond range for hybrid perovskites, which are competitive with conventional semiconductors like GaAs.

Spin lifetimes in perovskites are influenced by several factors, including defects, temperature, and external fields. At low temperatures, spin lifetimes can exceed 10 ns due to reduced phonon scattering and defect-related spin relaxation. However, at room temperature, spin lifetimes typically decrease to sub-nanosecond scales because of enhanced spin-flip scattering. The presence of organic cations also affects spin coherence, as their dynamic disorder introduces additional spin relaxation channels. Despite these challenges, perovskites exhibit relatively long spin lifetimes compared to other solution-processable materials, making them attractive for room-temperature spintronics.

Magnetic doping is a powerful strategy to tailor the spintronic properties of perovskites. Incorporating transition metals like Mn introduces localized magnetic moments that interact with the host's electronic spins. In Mn-doped CsPbCl3, for example, the dopant ions create exchange interactions that lead to giant Zeeman splitting under external magnetic fields. This splitting can exceed 100 meV at low temperatures, as demonstrated by magneto-optical measurements. The exchange interaction between Mn ions and the perovskite lattice also induces ferromagnetic ordering in certain compositions, enabling spin-polarized transport. The Curie temperature of these systems depends on the doping concentration and perovskite structure, with some materials showing ferromagnetism above 100 K.

Proximity effects further enrich the spintronic behavior of perovskites when interfaced with magnetic materials. Coupling perovskites to ferromagnetic layers, such as cobalt or permalloy, induces spin polarization at the interface due to exchange interactions. This proximity effect can enhance spin injection efficiency and reduce the impedance mismatch common in heterostructures. Studies on perovskite-ferromagnet bilayers have shown significant spin polarization at the interface, as detected by spin-resolved photoemission spectroscopy. The interfacial spin texture can also be modulated by electric fields, offering additional control over spin-dependent phenomena.

The combination of Rashba splitting, spin-orbit coupling, and magnetic interactions in perovskites opens avenues for novel spintronic functionalities. For instance, the non-trivial spin textures arising from Rashba splitting can be harnessed for spin-filtering devices or spin-orbit torque applications. The ability to tune these properties through composition, strain, or external fields provides flexibility in designing perovskite-based spintronics. Moreover, the solution-processability of perovskites allows for scalable fabrication of spin-active layers, which is advantageous for practical applications.

Challenges remain in optimizing perovskite spintronics, particularly in achieving long spin lifetimes at room temperature and minimizing defect-induced spin scattering. Advances in material synthesis, such as improved crystallinity and reduced trap densities, are critical for enhancing spin coherence. Additionally, understanding the microscopic mechanisms of spin relaxation and magnetic interactions will guide the development of high-performance spintronic devices.

In summary, perovskites exhibit a rich array of spintronic properties driven by Rashba splitting, spin-orbit coupling, and magnetic doping. Their compatibility with magnetic proximity effects further expands their potential for spin-based applications. While challenges persist, the unique advantages of perovskites position them as a compelling candidate for next-generation spintronics. Continued research into their spin-related phenomena will unlock new opportunities for exploiting these materials in spin manipulation and transport technologies.