Structural design of cubic Sr,V:CeFeO3 thin films with a strong magneto-optical effect and high compatibility with a Si substrate

Abstract

This paper focuses on strong magneto-optical thin films that closely match a Si substrate. The orthorhombic perovskite crystal structure of CeFeO₃ was optimized to a cubic perovskite structure by introducing strontium and vanadium ions into lattice. The cubic Ce_1−xSr_xFe_1−xV_xO₃ (x = 0.3, 0.5, 0.7) thin films with high quality and high growth orientation were prepared on a Si substrate by using the RF magnetron sputtering method. Moreover, the birefringence effect, which may weaken the magneto-optical effect, should not occur in the cubic thin film. The calculation results based on density functional theory show that the increased electronic transition probability is attributed to the strong spin-coupling between the hybrid Ce³⁺ 4f and Fe³⁺/V⁴⁺ 3d states. The magnetic circular dichroism ellipticity |Ψ_F| of the Ce_0.7Sr_0.3Fe_0.7V_0.3O₃ thin film is up to 4300 deg. cm⁻¹, which indicates a strong magneto-optical effect. Therefore, the cubic Ce_1−xSr_xFe_1−xV_xO₃/Si film with high Ce³⁺ concentration is expected to be a new candidate for integrated magneto-optical devices.