Molecular-Beam Epitaxial Growth and Structures of Dy on (100) and (211)Cr Thin Films

Abstract

We studied the crystal growth and structures of hexagonal close-packed Dy layers grown on body-centered cubic (100) and (211)Cr thin films using molecular-beam epitaxy. The (100) and (211)Cr films with smooth surfaces were prepared by growing Cr on (100) and (110)MgO substrates, respectively. The Dy layers were grown on these Cr thin films. During growth, surface structures were monitored by reflection high-energy electron diffraction. After growth, X-ray diffractometry was performed to analyze film structures. We found that Dy layers grow epitaxially on (100)Cr at 50 °C with two types of predominant domain: Dy(0001)[2110] ∥ Cr(100)[001] and Dy(0001)[0110] ∥ Cr(100)[001]. We also found that (1012)Dy grows epitaxially at 50 °C on (211)Cr with a tilt of approximately 3.7°. The orientational relationship is tilted-Dy(1012)[1210] ∥ Cr(211)[111]. These orientational relationships were discussed in connection with crystal structures and geometrical relationships. We show that the observed orientational relationships can be successfully explained in terms of strain with the aid of geometrical consideration.

Structural and Magnetic Properties of Dy/Cr Multilayers and Bilayers Grown by Molecular-Beam Deposition

“…The details of the growth procedures and the RHEED and XRD characterizations are given elsewhere. 9,10) The dependences of the magnetization of the samples on magnetic field strength and temperature were measured using a superconducting quantum interference device (SQUID) magnetometer. A magnetic field was applied both parallel and perpendicular to the film plane.…”

Growth Behavior of Dy/Cr Multilayers during Molecular-Beam Epitaxy and Their Structures

“…Bearing these aspects in mind, we have studied the epitaxial growth of Dy on Cr and analyzed its orientational relationships. 3) In this study, we grew Dy/Cr multilayers on MgO substrates using a molecular-beam epitaxy technique. The objective of this study is to report the growth behavior and structures of the Dy/Cr multilayers.…”

“…Details of the growth procedures and the RHEED and XRD characterizations are given elsewhere. 3) The RHEED and XRD analyses showed that the orientational relationships between the Cr buffer layer and the MgO substrate are Cr(100)[001] k MgO(100)[011] and Cr(211) [ 1 111] k MgO(110) [ 1 110]. 3) Figure 1 shows a series of RHEED patterns during the growth of a [Cr (1.8 nm)/ Dy (2.5 nm)] 20 multilayer at 50 C on buffer-(100)Cr/ (100)MgO.…”

“…3) The RHEED and XRD analyses showed that the orientational relationships between the Cr buffer layer and the MgO substrate are Cr(100)[001] k MgO(100)[011] and Cr(211) [ 1 111] k MgO(110) [ 1 110]. 3) Figure 1 shows a series of RHEED patterns during the growth of a [Cr (1.8 nm)/ Dy (2.5 nm)] 20 multilayer at 50 C on buffer-(100)Cr/ (100)MgO. From pattern (a), it was found that Dy exhibits repeatedly, as shown in (e) and (f).…”