Temperature field driven polar nanoregions in KTa_1−xNb_xO₃

Correlated disorder, which exists more widely in materials than crystalline phases, is beneficial for the improvement of material properties. KTa_1−xNb_xO₃ (KTN), a type of perovskite crystal, is recognized as a correlated disorder system in the vicinity of the Curie temperature, T_c, because of the existence of polar nanoregions (PNRs), which yield scale-free optics, reprogrammable soliton nonlinearity, and giant electro-optic effects. In this letter, we propose the mechanisms for induced PNR reorientation under a specific temperature field and manipulate PNRs using a temperature gradient in KTN to modulate light polarization, reduce light scattering, and enhance the electro-optic effect. A designed temperature gradient provides an effective way to drive correlated disordered PNRs, which could guide the exploitation of PNRs and is significant for correlated disorder applications.