Researchers from the Brazilian Center for Research in Physics (CBPF) and other institutions have uncovered a new regime of structural irreversibility in a specific type of manganite, a complex oxide material known for its unique electronic and magnetic properties. The team, led by Guilherme Kuhl-Soares and Otávio Canton, utilized temperature cycling Raman spectroscopy to study the behavior of La0.275Pr0.35Ca0.375MnO3 (LPCMO), a highly-correlated manganite that exhibits phase separation and charge and orbital ordering at certain temperatures. Their findings were recently published in the journal Nature Communications.
The researchers discovered that, as the material is cycled through different temperatures, its structural state becomes irreversible, meaning it does not return to its original state even after the temperature is restored to its initial value. This irreversibility arises from the interplay between lattice distortions and the competition between different electronic phases in the material. The team observed that the material’s history, or the specific path of temperature changes it undergoes, significantly influences its final structural and electronic state. This phenomenon is known as a thermal memory effect.
The study also revealed that the material’s magnetic and transport properties are closely coupled with its structural state, demonstrating a new form of nonequilibrium phase dynamics in mixed valence oxides. These findings advance the understanding of metastability and memory phenomena in strongly correlated materials, which are materials where the electrons interact strongly with each other and with the atomic lattice, leading to complex and often unexpected behaviors.
The practical implications of this research for the energy sector could be significant. The understanding of thermal memory effects and nonequilibrium dynamics in these materials could lead to the development of new types of adaptive and neuromorphic devices. These devices could potentially be used in energy storage and conversion systems, where the ability to remember and respond to past conditions could improve efficiency and performance. Additionally, the unique electronic and magnetic properties of these materials could be harnessed for advanced sensors and actuators in energy systems. However, further research and development will be needed to translate these fundamental findings into practical applications.
In summary, the researchers have uncovered a new regime of structural irreversibility and thermal memory effects in a highly-correlated manganite, shedding light on the complex interplay between lattice distortions and electronic phases in these materials. Their findings, published in Nature Communications, open up new avenues for the development of adaptive and neuromorphic functionalities in quantum materials, with potential applications in the energy sector.
This article is based on research available at arXiv.