Synthesis of λ-Ti3O5 nanocrystals using a block copolymer

In this study, λ-Ti3O5 nanocrystals are synthesized by preparing a precursor using a block copolymer. The highly pure λ-Ti3O5 has a flake-like morphology with a particle size of 450±130 nm and is composed of nanocrystal aggregates with a size of 22±8 nm. The magnetic susceptibility shows a Pauli paramagnetic behavior from 2 K to 600 K, indicating that λ-Ti3O5 is stable over a wide temperature region. The heat energy associated with a phase transition from β-Ti3O5 to λ-Ti3O5 accumulates at 457 K. The threshold pressure to induce a phase transition from λ-Ti3O5 to β-Ti3O5 and extract the accumulated heat energy is ~300 MPa. The present synthesis may be applicable to realize a property-tunable heat storage ceramic of λ-Ti3O5.