Abstract: An electrode catalyst layer includes a catalyst material, a conductive carrier, which supports the catalyst material, a polymer electrolyte, and a fibrous material. The electrode catalyst layer includes a three-dimensional network of a flow path. The flow path includes a plurality of terminal points and a plurality of branches. Each of the branches is an elongated hole connecting a pair of the terminal points. The plurality of branches include a bifurcated branch. One of the pair of the terminal points of the bifurcated branch is connected to another branch. The number of branches per unit volume of the electrode catalyst layer is 8500 or more and 13000 or less. The unit volume is defined as 3.9 ?m×3.9 ?m×4.4 ?m.

Abstract: A method for forming a pattern of metal oxide capable of selectively etching an etching object containing metal oxide relative to a non-etching object and forming a pattern of the metal oxide along a pattern of the non-etching object serving as a template. Metal oxide containing oxide of at least one of tin and indium is etched using an etching gas to form the pattern of the metal oxide. An etching gas containing halon is brought into contact with a member to be etched in the presence of plasma, and etching is performed while a bias power is applied to a lower electrode (2) supporting the member to be etched to selectively etch a metal oxide layer (22) relative to a silicon substrate (24), a template layer (21), and an underlying layer (23), and the predetermined pattern of the template layer (21) is transferred to the metal oxide layer (22).

Abstract: An electrode catalyst layer includes a catalyst material, a conductive carrier that supports the catalyst material, a polymer electrolyte containing a sulfonate group, and a fibrous material. The electrode catalyst layer includes a first surface configured to be in contact with the polymer electrolyte membrane, and a second surface facing away from the first surface. A first value is obtained by dividing a peak intensity of SO3 (m/z80) by a peak intensity of carbon (m/z12), and also dividing by a total thickness of the electrode catalyst layer, when the electrode catalyst layer is analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) at each of a plurality of positions in a thickness direction of the electrode catalyst layer from the first surface to the second surface. A rate of change of the first value with respect to a thickness of the electrode catalyst layer is ?0.0020 or less.

Abstract: An electrode catalyst layer includes a catalyst material, a conductive carrier, which supports the catalyst material, a polymer electrolyte, and a fibrous material. The electrode catalyst layer includes a three-dimensional network of a flow path. The flow path includes a plurality of terminal points and a plurality of branches. Each of the branches is an elongated hole connecting a pair of the terminal points. The plurality of branches include a bifurcated branch. One of the pair of the terminal points of the bifurcated branch is connected to another branch. The number of branches per unit volume of the electrode catalyst layer is 8500 or more and 13000 or less. The unit volume is defined as 3.9 ?m×3.9 ?m×4.4 ?m.

Abstract: An electrode catalyst layer includes a catalyst material, a conductive carrier that supports the catalyst material, a polymer electrolyte containing a sulfonate group, and a fibrous material. The electrode catalyst layer includes a first surface configured to be in contact with the polymer electrolyte membrane, and a second surface facing away from the first surface. A first value is obtained by dividing a peak intensity of SO3 (m/z80) by a peak intensity of carbon (m/z12), and also dividing by a total thickness of the electrode catalyst layer, when the electrode catalyst layer is analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) at each of a plurality of positions in a thickness direction of the electrode catalyst layer from the first surface to the second surface. A rate of change of the first value with respect to a thickness of the electrode catalyst layer is ?0.0020 or less.