The Structural Evolution of $(\hbox{Gd}, \hbox{Y}) \hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{\rm x}$ Tapes With Zr Addition Made by Metal Organic Chemical Vapor Deposition

Abstract

Structural analysis of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(\hbox{Gd}, \hbox{Y})\hbox{Ba}_{2}\hbox{Cu}_{3} \hbox{O}_{x}$</tex></formula> tapes with Zr addition made by metal organic chemical vapor deposition has been conducted with transmission electron microscopy and X-ray diffraction. Zr content in the films was varied from 0 to 25 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\%$</tex></formula> in the precursor. In all Zr-doped films, self-assembled nanocolumnar structures of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{BaZrO}_{3}$</tex></formula> (BZO) were observed along the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$c$</tex></formula> -axis. The amount of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\hbox{BaZrO}_{3}$</tex></formula> was found to increase steadily with Zr content. Additionally, planar BZO plates were found on the (001) plane of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(\hbox{Gd}, \hbox{Y})\hbox{Ba}_{2} \hbox{Cu}_{3}\hbox{O}_{x}$</tex></formula> film. The size and thickness of BZO plates were seen to increase with Zr doping level. Rare-earth copper oxide phases were observed to begin to emerge in the 20 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\%$</tex></formula> Zr-doped film. Cross-sectional study of the interface between <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(\hbox{Gd}, \hbox{Y})\hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{\rm x}$</tex></formula> and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{LaMnO}_{3}$</tex></formula> cap layer revealed a thin discrete BZO layer on the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{LaMnO}_{3}$</tex></formula> in the 20 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\%$</tex></formula> Zr doped film.