Alkaline earth metal titanate crystal laminate

A structure having an alkaline earth metal titanate crystal nanoparticle on a surface of a crystal laminate,

• wherein the crystal laminate comprises:
• a crystal of an alkaline earth metal titanate as a constitutional unit, wherein:
• the crystal is a cubic crystal, a tetragonal crystal or an orthorhombic crystal;
• the crystal has a primary particle diameter of 500 nm or less;
• and
• the crystal is layered with an orientation in a {100} plane direction thereof,
• wherein
• the crystal laminate has an average width of more than 1 μm,
• the crystal laminate has an average thickness of 50 am or more,
• the crystal laminate has a ratio (average width/average thickness of the average width to the average thickness of 10 to 100,
• the crystal present on a surface of the crystal laminate has a primary particle diameter of 2 to 20 times more than a primary particle diameter of the crystal present in an interior of the crystal laminate,
• the crystal laminate has a specific surface area of 10 m2/g or more,
• a crystal orientation of the alkaline earth metal titanate crystal nanoparticle is in the same direction as that of the crystal laminate,
• the alkaline earth metal titanate crystal nanoparticle has a primary particle diameter of twice or more a primary particle diameter of the crystal present on the surface of the crystal laminate,
• a proportion of the nanoparticles on the surface of the crystal laminate is, in terms of surface coverage, 20% to 80%, and
• the alkaline earth metal titanate crystal nanoparticle has a primary particle diameter of 50 nm or more.