Nonlinear relaxational polarization in aluminum oxide

Frequency and electric field dependent measurements of the complex capacitance on Al
₂
O
₃
based metal-insulator-metal capacitors were conducted. A nonlinear relaxational polarization in Al
₂
O
₃
was investigated systematically by means of varying the thickness of the dielectric and characterizing samples at various temperatures. Employing the asymmetric double well potential model, where the charges fluctuate between two potential minima, we show that the relaxational polarization in metal oxide can be interpreted.