Rodlike YMn₂O₅ Powders Derived from Hydrothermal Process Using Oxygen as Oxidant

A facile approach is proposed herein to fabricate YMn₂O₅ powders with the hydrothermal method with oxygen as an oxidant. The structure and morphology of the as-synthesized YMn₂O₅ powders were characterized by XRD, SEM, and high-resolution transmission electron microscopy (HRTEM). The results manifested that the main factors that affected the formation of the rod-like YMn₂O₅ structures were the stirring time, hydrothermal temperature, and hydrothermal time. The oxidation time in the air had a remarkable effect on the final product by oxidizing Mn²⁺ ions to Mn³⁺ ions and Mn⁴⁺ ions. The obtained YMn₂O₅ powder was single crystalline and possessed a nanorod morphology, where the growth direction was along the c axis. The possible formation mechanism involved a dissolution-crystallization mechanism. Under the 397 nm excitation, the Mn⁴⁺ ions exhibited an intense orange emission at 596 nm. The energy bandgap of YMn₂O₅ powders was 1.18 eV.