Preprint Article Version 1 This version is not peer-reviewed

# First-Principles Prediction of Skyrmionic Phase Behavior in GdFe$_2$ Films Capped by 4$D$ and 5$D$ Transition Metals

Version 1 : Received: 17 January 2019 / Approved: 24 January 2019 / Online: 24 January 2019 (07:36:44 CET)
Version 2 : Received: 12 February 2019 / Approved: 13 February 2019 / Online: 13 February 2019 (10:33:34 CET)

A peer-reviewed article of this Preprint also exists.

Jekal, S.; Danilo, A.; Phuong, D.; Zheng, X. First-Principles Prediction of Skyrmionic Phase Behavior in GdFe2 Films Capped by 4d and 5d Transition Metals. Appl. Sci. 2019, 9, 630. Jekal, S.; Danilo, A.; Phuong, D.; Zheng, X. First-Principles Prediction of Skyrmionic Phase Behavior in GdFe2 Films Capped by 4d and 5d Transition Metals. Appl. Sci. 2019, 9, 630.

Journal reference: Appl. Sci. 2019, 9, 630
DOI: 10.3390/app9040630

## Abstract

In atomic GdFe$_2$ films capped by 4$d$ and 5$d$ transition metals, we show that skyrmions with extremely reduced diameters of a smaller than 12 nm can occur. The Dzyaloshinskii-Moriya interaction (DMI), exchange energy, and the magnetocrystalline anisotropy (MCA) energy were investigated based on density functional theory. Since DMI and MCA are caused by spin-orbit coupling, they are increased with 5$d$ capping layers compared to films capped by 4$d$ transition metal. We discovered a skyrmion phase by using atomistic spin dynamics simulations at small magnetic fields of $\sim$ 1 T. A ground state that a spin spiral phase is remained even at zero magnetic field for both films with 4$d$ and 5$d$ capping layers.

## Subject Areas

Skyrmion; Dzyaloshinskii–Moriya interaction; exchange energy; magnetic anisotropy