Structure analysis of Ni thin films epitaxially grown on bcc metal underlayers formed on MgO(100) substrates

Ni thin films are prepared on Cr, V, and Nb underlayers with bcc structure formed on MgO(100) single-crystal substrates by molecular beam epitaxy. The growth behavior and the crystallographic properties are investigated by in-situ reflection high-energy electron diffraction and pole-figure X-ray diffraction. Cr(100) and V(100) single-crystal underlayers grow epitaxially on the substrates, whereas an Nb epitaxial_underlayer consisting of two bcc(110) variants is formed on the MgO(100) substrate. Metastabl

Structure analysis of Ni thin films epitaxially grown on bcc metal underlayers formed on MgO(100) substrates

Ni thin films are prepared on Cr, V, and Nb underlayers with bcc structure formed on MgO(100) single-crystal substrates by molecular beam epitaxy. The growth behavior and the crystallographic properties are investigated by in-situ reflection high-energy electron diffraction and pole-figure X-ray diffraction. Cr(100) and V(100) single-crystal underlayers grow epitaxially on the substrates, whereas an Nb epitaxial_underlayer consisting of two bcc(110) variants is formed on the MgO(100) substrate. Metastable crystals nucleate on the Cr and the V underlayers, where the metastable hcp structure is stabilized through heteroepitaxial growth. With increasing the film thickness, the hcp structure starts to transform into more stable fcc structure by atomic displacement parallel to the hcp(0001) close-packed plane. The resulting films are consisting of mixtures of hcp and fcc crystals. On the other hand, only the formation of fcc crystal is recognized for the Ni film grown on Nb(110) underlayer

Metastable Sm(Fe,Cu)

Sm-Fe thin films are prepared on Cu(111) underlayers hetero-epitaxially grown on MgO(111) single-crystal substrates by using an ultra-high vacuum molecular beam epitaxy system. The Sm/Fe composition is varied from Fe-rich (10 at. % Sm - Fe) to Sm-rich (30 at. % Sm - Fe) region including SmFe5 stoichiometry. The influence of film composition on the film structure is studied by in-situ reflection highenergy electron diffraction and X-ray diffraction. Metastable Sm(Fe,Cu)5 ordered phase formation is recognized in the Sm-Fe films with the investigated compositions. Cu atoms diffuse from the underlayer into the Sm-Fe film and substitute the Fe site in SmFe5 structure forming an alloy compound of Sm(Fe,Cu)5. The Sm-Fe films with Fe-rich compositions consist of Sm(Fe,Cu)5 and bcc-Fe phases, whereas the Sm-Fe films with Sm-rich compositions consist of Sm(Fe,Cu)5 and amorphous phases. Cu atom diffusion into Sm-Fe film is assisting the formation of ordered phase

Formation of Sm(Co

Sm17(Co1–xNix)83 (at. %, x = 0, 0.2, 0.8, 1) alloy thin films are prepared on Cu(111) underlayers hetero-epitaxially grown on MgO(111) substrates by molecular beam epitaxy. The effects of substrate temperature and Ni/Co composition on the growth behavior and the detailed resulting film structure are investigated. Formation of RT5 ordered phase is enhanced with increasing the substrate temperature and the Ni composition. The long-range order degrees of Sm17Co83, Sm17(Co0.8Ni0.2)83, Sm17(Co0.2Ni0.8)83, and Sm17Ni83 films deposited at 500 °C are estimated to be 0.77, 0.82, 0.89, and 0.97, respectively. The Sm17(Co1–xNix)83 films with RT5 structure consist of two types of epitaxial (0001) variant whose orientations are rotated around the film normal by 30° each other. With increasing the Ni content ratio of x from 0 to 1, the volume ratio of two variants is varied from 53:47 to 94:6. The nucleation of only one-type variant with a smaller lattice mismatch with respect to Cu underlayer is promoted with increasing the Ni content ratio

Ordered phase formation in Sm-Ni thin film deposited on Cr(100) single-crystal underlayer

Sm17Ni83 (at. %) alloy thin films are prepared on Cr(100) underlayers hetero-epitaxially grown on MgO(100) single-crystal substrates by employing an ultra-high vacuum molecular beam epitaxy system. The effect of substrate temperature on the ordered phase formation is investigated. The films deposited below 300 °C consist of amorphous phase, whereas formation of SmNi5 ordered phase is recognized for the films deposited above 400 °C. The SmNi5 films with ordered phase consist of two types of (11$\bar 2$0) variant whose c-axes are lying in the film plane and rotated around the film normal by 90° each other. With increasing the temperature from 400 to 500 °C, the long-range order degree increases from 0.65 to 0.80. The ordered film formed at 500 °C shows an in-plane magnetic anisotropy reflecting the magnetocrystalline anisotropy of SmNi5 crystal

Structure analysis of Ni thin films epitaxially grown on bcc metal underlayers formed on MgO(100) substrates

Ni thin films are prepared on Cr, V, and Nb underlayers with bcc structure formed on MgO(100) single-crystal substrates by molecular beam epitaxy. The growth behavior and the crystallographic properties are investigated by in-situ reflection high-energy electron diffraction and pole-figure X-ray diffraction. Cr(100) and V(100) single-crystal underlayers grow epitaxially on the substrates, whereas an Nb epitaxial_underlayer consisting of two bcc(110) variants is formed on the MgO(100) substrate. Metastabl