A systematic study of texturing mechanisms in pure Ag is presented, the goal being to obtain a cube textured {100}001 tape that can be used as a substrate for superconducting coated conductors. It is shown that a sharp cube texture can be produced after pre-heated deformation and recrystallization. Optimal parameters are detailed. 99.99% pure Ag powder is used as starting material. Fine grained (15 µm) Ag ingots are pre-heated at 100 °C before standard cold rolling. The effect of pre-heating on deformation texture is to change the main texture from the brass orientation {110}112 to the Goss {110}001 one. The presence of a copper-type texture with relatively high values of the ODF (oriented distribution function) after the 100 °C pre-heated deformation can be understood as a slight increase of the stacking fault energy of Ag during the pre-heated deformation. The optimal annealing is achieved at 700 °C for 30 min in a primary vacuum. This leads to a sharp cube texture. The FWHM values of the three x-ray pole figures are, at no more than 10°, the smallest ever reported for cube textured Ag tapes. The formation of cube texture is interpreted in terms of orientation nucleation and orientation growth theories that play a common role during the texturing process. The stability of cube texture at high temperature up to 900 °C indicates that the tapes are suitable for epitaxial growth of superconducting oxides.
Texture development in pure Ag was investigated in order to
obtain {110}⟨uvw⟩ textured Ag ribbons that can be used as
a substrate for YBa2Cu3O7 superconducting coated
tapes without any buffer layer. The starting material was 99.95% pure
commercial Ag foils. A 20% deformation reduction was used at each step of
the cold rolling process after which an optimal annealing was achieved at
800 °C for 4 h in a primary vacuum. This process leads to
large-grain ribbons with the {110}⟨112⟩ orientation. A
sharp and pure texture is obtained with a FWHM smaller than 6° in
the three x-ray pole figures that were used to calculate the orientation
distribution function. Crystallographic orientation maps achieved by
electron back-scattering diffraction show a misorientation from the normal
direction of less than 4°. A twinning mechanism is used to explain
the formation of the {110}⟨112⟩ texture. The stability of
the {110}⟨112⟩ texture is confirmed by further annealings
up to 900 °C, a practical temperature for coated tapes preparation.
Lengths up to 25 cm with a uniform {110}⟨112⟩ texture have
been obtained.
The aim of our work is to produce biaxially aligned HTS conductors by epitaxial growth on textured Ag. This paper will focus on the preparation of long length textured Ag ribbons.After cold rolling and annealing in vacuum at 800"C, different { llO}cuvw> directions appear in the recrystallized pure Ag ribbons. The {11O}c112> texture is obtained after cold rolling by adding a 500°C step before the annealing at 800°C. If the Ag ingots are annealed at 600°C in vacuum before the cold rolling, the 800°C annealing leads to a sharp {11O}cO11> texture. The quality of the texture is studied by X-ray and electronic diffraction. Three X-ray pole figures are used to calculate the ODF function, a SEM is used to obtain orientation maps from EBDP. The surface roughness is studied by AFM. We have produced lengths of 25 cm with a sharp {110}<112> texture (FWHM=7", ODF peak). The characteristics of the two { 110}<112> and {11O}cO11> orientation are presented in details.It is shown that those {llO} ribbons are suitable for epitaxial growth of superconducting cuprates. The Ag textured ribbons are used as substrates for different superconducting systems such as TI-1223 and Y123.
YBCO films were deposited on (100), ( 110) and ( 111) oriented silver single crystals and {100} 100 , {110} 211 and {012} 100 biaxially textured Ag substrates by pulsed laser deposition. It is shown that the (100) and ( 110) orientated single crystals and the {110} biaxially textured Ag tape are all suitable for the deposition of YBCO thin films with c-axis in-plane alignment. The J c of YBCO film deposited on {110} 211 biaxially textured Ag foil is 7 × 10 5 A cm −2 at 77 K, 0 T. A scheme for the regular growth of YBCO on silver was put forward.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.