Embodiments include a heating device for heating a workpiece, including a furnace defining a closed space insulated from an exterior and surrounded by a heat insulator, a heater disposed in the furnace to heat a workpiece, a bar-shaped support element for supporting a workpiece in the furnace, and bases holding longitudinal ends of the support element for mounting the support element on a wall of the furnace, the support element being configured to increase the bending strength against sagging between its longitudinal ends.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion out of the sintering electrolyte. Li-stuffed garnet setter plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone to diffuse out of the solid electrolyte.

The present invention provides a heat treatment jig. A metal wire as a heat treatment target is to be wound around the jig. The jig comprises a cylindrical tubular body whose outer wall surface has a helical groove formed along a circumferential direction to wind the metal wire. A depth of the groove is larger than a length at which the metal wire will isolate from the groove when the metal wire wound along the groove at room temperature is thermally expanded by being heated to a predetermined heat treatment temperature.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion out of the sintering electrolyte. Li-stuffed garnet setter plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone, to diffuse out of the solid electrolyte.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion out of the sintering electrolyte. Li-stuffed garnet setter plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone to diffuse out of the solid electrolyte.

The present invention provides a heat treatment jig. A metal wire as a heat treatment target is to be wound around the jig. The jig comprises a cylindrical tubular body whose outer wall surface has a helical groove formed along a circumferential direction to wind the metal wire. A depth of the groove is larger than a length at which the metal wire will isolate from the groove when the metal wire wound along the groove at room temperature is thermally expanded by being heated to a predetermined heat treatment temperature.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion out of the sintering electrolyte. Li-stuffed garnet setter plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone to diffuse out of the solid electrolyte.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion qui of the sintering electrolyte, Li-stuffed garnet seller plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone to diffuse out of the solid electrolyte.

Provided is a heat treatment container having a small size and capable of efficiently performing a heat treatment on a SiC substrate. A heat treatment container is a container for a heat treatment on a SiC substrate 40 under Si vapor pressure. The SiC substrate 40 is made of, at least in a surface thereof, single crystal SiC. The heat treatment container includes a container part 30 and a substrate holder 50. The container part 30 includes an internal space 33 in which Si vapor pressure is caused. The internal space 33 is partially open. The substrate holder 50 is able to support the SiC substrate 40. When the substrate holder 50 supports the SiC substrate 40, an open portion of the container part 30 is covered so that the internal space 33 is hermetically sealed.

Setter plates are fabricated from Li-stuffed garnet materials having the same, or substantially similar, compositions as a garnet Li-stuffed solid electrolyte. The Li-stuffed garnet setter plates, set forth herein, reduce the evaporation of Li during a sintering treatment step and/or reduce the loss of Li caused by diffusion out of the sintering electrolyte. Li-stuffed garnet setter plates, set forth herein, maintain compositional control over the solid electrolyte during sintering when, upon heating, lithium is prone, to diffuse out of the solid electrolyte.