Ceramic substrate, aln single crystal, aln whisker, and aln whisker composite

A ceramic substrate comprising an AlN whisker in a base body thereof, the AlN whisker including a fibrous AlN single crystal having a hexagonal wurtzite structure and an oxygen-containing layer covering a surface of the AlN single crystal, wherein an oxygen concentration is 7.0 mass % or less.

A ceramic substrate comprising an AlN whisker composite including a plurality of AlN whiskers in a base body thereof, each of the plurality of AlN whiskers including a fibrous AlN single crystal having a hexagonal wurtzite structure and an oxygen-containing layer covering a surface of the AlN single crystal, wherein a content ratio of AlN whiskers having a diameter of less than 1.0 μm is 20 vol % or less.

A fibrous AlN single crystal having a hexagonal wurtzite structure, wherein a ratio of a (10-10) plane peak intensity to a (0002) plane peak intensity obtained when an X-ray is emitted to an end surface in a plate thickness direction is 2.00 or more.

An AlN whisker comprising a fibrous AlN single crystal having a hexagonal wurtzite structure and an oxygen-containing layer covering a surface of the AlN single crystal, wherein an oxygen concentration is 7.0 mass % or less.

An AlN whisker composite comprising a plurality of AlN whiskers, each of the plurality of AlN whiskers including a fibrous AlN single crystal having a hexagonal wurtzite structure and an oxygen-containing layer covering a surface of the AlN single crystal, wherein a content ratio of AlN whiskers having a diameter of less than 1.0 μm is 20 vol % or less.