Nanocluster‐Mediated Magnetoelectric and Pseudocapacitive Coupling in an As‐Quenched PbTiO ₃ ‐Based Oxide Glass

ABSTRACT

The emergence of coupled ferroic functionalities in structurally disordered systems remains a major challenge because the lack of long‐range order usually suppresses cooperative interactions. Here, we report, for the first time, magnetoelectric and pseudocapacitive coupling in an as‐quenched PbTiO ₃ ‐containing multicomponent oxide glass (20PbTiO ₃ –15Fe ₂ O ₃ –15Co ₃ O ₄ –50B ₂ O ₃ , mol%). XRD and HRTEM analyses reveal nanoclusters (∼13 nm) embedded in an amorphous matrix, creating significant interfacial heterogeneity. Dielectric measurements indicate superparaelectric behavior from polar clusters, while magnetic measurements confirm superparamagnetism associated with confined magnetic nanoclusters. Electric field‐dependent magnetization demonstrates reproducible modulation of the M–H response with a magnetoelectric coupling coefficient of ∼1.1 × 10 ^{− 5} s/m. The coupling originates from strain‐ and charge‐mediated interactions at nanocluster/glass interfaces, showing that nanoscale heterogeneity can induce cross‐field coupling in a non‐intrinsically multiferroic glass. The glass also exhibits a recoverable energy storage density of 1.2 J/cm ³ with ∼90% efficiency. Electrochemical analysis reveals dominant pseudocapacitive behavior ( b ≈ 0.91), suggesting that the same interfacial heterogeneity responsible for ferroic coupling also enhances the reversible redox activity. These findings provide a pathway for integrating magnetoelectric and electrochemical functionalities in disordered glass systems without long‐range crystalline order.