Sharp Kabushiki Kaisha Corporation

Yasunari Okamoto

Hirotaka Ohno

Hironori Matsunaga

Yoshiharu Nakajima

Yoshiro Akagi

Hiroshi Taniguchi

Mariko Ishino

Atsuhisa Inoue

Shigeru Kaminishi

Hideo Asahina

Koji Ohoka

A cation exchange polyimide resin having resistance to organic solvents which contains polyamidocarboxylic acid units providing sites of ion exchange and represented by the formula (I): ##STR1## wherein R.sup.1 is a tetravalent organic group, and R.sup.2 is a bivalent organic group, which is capable of trapping cations from organic solvents.

Cation exchange polyimide resin and use thereof

A method for evaluating a lithium niobate thin film includes measuring an absorption edge wavelength of a lithium niobate thin film and evaluating a lithium-to-niobium composition ratio of the thin film, and an apparatus for preparing a thin film including a thin film-forming body capable of controlling the lithium-to-niobium composition ratio of a lithium niobate thin film being formed and an evaluation device for evaluating the lithium-to-niobium composition ratio, the evaluation device being provided with a monitor substrate, an optical path for spectrometry, an ultraviolet ray source and a measurement part for measuring an absorption edge wavelength of the thin film.

Method for evaluating a lithium niobate thin film and apparatus for

A method of producing a ferroelectric thin film comprising the steps of evaporating metal Li or an oxide thereof as a Li source, metal Nb or an oxide thereof as a Nb source and metal Ta or an oxide thereof as a Ta source in a substantially oxygen gas plasma atmosphere while controlling the respective heating temperatures independently from each other and simultaneously depositing the Li, Nb and Ta on a substrate so as to obtain an LiNb.sub.1-x Ta.sub.x O.sub.3 (0&lt;x&lt;1) thin film which shows ferroelectricity.

Method of producing ferroelectric LiNb.sub.1-31 x Ta.sub.x O.sub.3

Growing community of inventors

Nara, Japan

Yasunari Okamoto