"Nanotechnology and nanomaterials"
Spectral dependence of Faraday effect enhancing 
in the thin film structure Eu2O3/Fe
A.M. Kasumov, V.M. Karavaeva, K.O. Shapoval, V.O. Lukashevych, G.V. Lashkarov
Frantsevych Institute of Problems of Materials Science, National Academy of Sciences of Ukraine, 3, Krzhyzhanovsky st., Kyiv, 03142, Ukraine. 
e-mail: kasumov@ipms.kiev.ua
Thin film magneto-optical sensors are used in various devices: read-write and recording systems, gyroscopes, displays, and others. Increasing of a sensitivity of sensors in such devices is an urgent condition for expanding their use. One of the ways to increase of a sensitivity of magneto-optical sensors opens in thin-film structures consisting of contacting layers of rare-earth metal (REM) oxides and iron group metals (Fe, Co, Ni). Recently, it has been found that on the boundary of the contact of layers in the structures of metal (Fe, Co, Ni) /REM oxide there is an exchange f-d interaction between the incomplete f- and d-electron shells of the atoms of the transitional elements that are part of these layers. This interaction under certain conditions leads to an increase in the magnetization of metals (Fe, Co, Ni). In turn, the growth of magnetization causes amplification of the galvanomagnetic (magnetoelectric) [1] and magneto-optical (Faraday effect) properties that depend on it. This can help to increase the sensitivity of sensors using such properties. In this paper, the spectral dependence of the Faraday effect enhanced by the above-described method on the example of the film structure of Eu2O3/Fe is considered.
The figure shows the dependence of the increase of the Faraday angle,where , - the angles after and before applying Eu2O3 layer in the thickness of 24 nm to the Fe layer, on the wavelength of light λ in the absence (1) and with the inclusion (2) of an external magnetic field of intensity 400 E to the film structure of Eu2O3/Fe.
It is clear from the figure that the spectral dependences have the form of curves with a minimum. The largest increase on the Faraday angle is achieved in the short-wave (λ = 450 nm) region of visible radiation. The attachment of an external magnetic field leads to an even greater amplification of the Faraday effect, which makes this process promising for practical application.
1. Лашкарёв Г.В., Касумов А.М., Караваева В.М., Микитченко А.А., Румянцева Ю.Ю. Магнитное взаимодействие наноразмерных плёнок Ni и Dy2O3//Тр. Междунар. Конф. НАНСИС-2016.- 1-2 декабря 2016. - С.60