# Nanoscale Tracking of the High-Temperature Spin-State Transition in LaCoO3

## TL;DR

This paper studies how LaCoO3 changes at high temperatures at a nanoscale, which is important for improving brain-inspired computing devices.

## Contribution

The paper presents the first nanoscale in situ measurement of the spin transition in LaCoO3 at device-relevant temperatures.

## Key findings

- Nanoscale spin-state transitions in LaCoO3 were measured at temperatures up to 325°C using STEM-EELS.
- An Al2O3 coating prevents unwanted reduction of LaCoO3 at high temperatures and vacuum.
- Understanding these transitions is crucial for optimizing neuromorphic devices based on LaCoO3.

## Abstract

The
high-temperature spin and electronic transitions in LaCoO3 have recently been leveraged to create neuromorphic (brain-inspired)
devices. While these devices have shown the potential for impactful
functionality in next-generation computing systems, the nanoscale
dynamics of the spin and electronic transitions that underlie their
operation are not well understood. Inhomogeneities related to interfaces,
electrode contacts, strain, and crystal defects can all affect device
performance, making nanoscale characterization of the transitions
essential for producing consistent and reliable devices. Here, we
demonstrate the first nanoscale in situ measurement of the spin transition
in LaCoO3 at device-relevant temperatures (25–325
°C) over length scales of tens of nanometers using STEM-EELS.
This measurement is enabled by an Al2O3 coating,
which prevents unwanted reduction of the LaCoO3 specimen
at high temperature and vacuum. The detailed understanding of LaCoO3 transition dynamics enabled by such measurements will be
crucial for optimizing LaCoO3-based neuromorphic devices
and increasing reliability for real-world application.