| 摘要 |
<p>A translucent ceramic composed mainly of a perovskite compound of the general formula: (Sr<SUB>1-s</SUB>Ba<SUB>s</SUB>)(M<SUB>x</SUB>B1<SUB>y</SUB>B2<SUB>z</SUB>)<SUB>v</SUB>O<SUB>w</SUB>. In the formula, B1 is at least one member selected from among Mg, Zn, In, Y, Sc, Ho, Tb and Sm, and B2 is at least one member selected from among Ta and Nb. M is at least one member selected from among Ti, Sn, Zr and Hf. The relationships 0=s<1, 0=x=0.7, 1.00=z/y=2.20, 1.00=v=1.07 and x+y+z=1 are satisfied, and w is a positive number required for maintaining of electrical neutrality. This translucent ceramic exhibits high refractive index and high anomalous dispersion and excels in optical characteristics, and can be advantageously used as a material of objective lens (2) fitted in optical pickup device (9).</p> |
