Abstract: The present invention provides an information provision system that provides a user with information for coping with a problem by using an information terminal having a camera and a display, wherein the information terminal includes at least one processor with a memory comprising instructions, that when executed by the at least one processor, cause the at least one processor to at least: identify a problem area in a captured image obtained by the camera; detect agitation of the user; and suitably display, on the display, a plurality of procedure screens indicating contents of a procedure for coping with the identified problem area, in accordance with an answer from the user, and the at least one processor is configured to change a procedure screen to be displayed on the display in response to detection of agitation of the user.

Abstract: An as-grown single crystal ingot of a dopant-containing metal oxide or quasi-binary compound is provided in which a lateral surface has a length L greater than or equal to 50 mm, there is a linear recess on the lateral surface, and, in the area surrounded by the lateral surface, the outer shape of the cross-section perpendicular to the length direction and positioned spaced 50 mm away in the length direction from the other end in the length direction without with the recess is such that, outside of the area formed by the line of intersection between the cross-section and a faceted surface, the maximum value of the distance X of the recess from an ideal outer shape is less than or equal to 5 mm.

Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? on an arbitrary straight line on the principal surface that passes through a center of the principal surface is not more than 0.7264. The ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s represents an angle defined by an X-ray incident direction and the principal surface at a peak position of an X-ray rocking curve on the straight line and ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.

Abstract: Provided are: a method for producing a ?-Ga2O3 substrate of which changes in donor concentration in a reducing atmosphere or an inert gas atmosphere are suppressed; and a method for producing a crystal laminate structure that can epitaxially grow a high-quality crystal film having low variability of quality in a reducing atmosphere or an inert gas atmosphere. The method for producing a ?-Ga2O3 substrate includes a step for cutting out a ?-Ga2O3 substrate from a ?-Ga2O3 crystal containing a group IV element; annealing processing in an atmosphere containing a reducing atmosphere and/or an inert gas atmosphere is performed on the ?-Ga2O3 crystal before cutting out the ?-Ga2O3 substrate, or on the cut-out ?-Ga2O3 substrate.

Abstract: A ?-Ga2O3-based single-crystal substrate includes a ?-Ga2O3-based single crystal, and a principal surface being a plane parallel to a b-axis of the ?-Ga2O3-based single crystal. A maximum value of ?? on an arbitrary straight line on the principal surface that passes through a center of the principal surface is not more than 0.7264. The ?? is a difference between a maximum value and a minimum value of values obtained by subtracting ?a from ?s at each of measurement positions, where ?s represents an angle defined by an X-ray incident direction and the principal surface at a peak position of an X-ray rocking curve on the straight line and ?a represents an angle on an approximated straight line obtained by using least-squares method to linearly approximate a curve representing a relationship between the ?s and the measurement positions thereof.

Abstract: Provided is a gallium oxide substrate which has less linear pits. Obtained is a gallium oxide substrate wherein the average density of linear pits in a single crystal surface is 1,000 pits/cm2 or less.

Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.

Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.

Abstract: A ?-Ga2O3-based single crystal substrate includes an average dislocation density of less than 7.31×104 cm?2. The average dislocation density may be not more than 6.14×104 cm?2. The substrate may further include a main surface including a plane orientation of (?201), (101) or (001). The substrate may be free from any twinned crystal.

Abstract: A Ga2O3-based single crystal substrate includes a main surface including BOW of not less than ?13 ?m and not more than 0 ?m. The main surface may further include WARP of not more than 25 ?m. The main surface may further include TTV of not more than 10 ?m.

Abstract: A ?-Ga2O3-based single crystal substrate includes a ?-Ga2O3-based single crystal. The ?-Ga2O3-based single crystal includes a full width at half maximum of an x-ray rocking curve of less than 75 seconds.

Abstract: Provided are: a method for producing a ?-Ga2O3 substrate of which changes in donor concentration in a reducing atmosphere or an inert gas atmosphere are suppressed; and a method for producing a crystal laminate structure that can epitaxially grow a high-quality crystal film having low variability of quality in a reducing atmosphere or an inert gas atmosphere. The method for producing a ?-Ga2O3 substrate includes a step for cutting out a ?-Ga2O3 substrate from a ?-Ga2O3 crystal containing a group IV element; annealing processing in an atmosphere containing a reducing atmosphere and/or an inert gas atmosphere is performed on the ?-Ga2O3 crystal before cutting out the ?-Ga2O3 substrate, or on the cut-out ?-Ga2O3 substrate.