| 摘要 |
PURPOSE:To obtain a magnetic and optical element having Faraday rotation ability made almost uniform over a wide temp. range by forming a mixed crystal with Y3Fe5O12 having Faraday rotation ability shown by a positive temp. coefft. and rare earth element-iron-garnet Gd3Fe5O12 having Faraday rotation ability shown by a negative temp. coefft. in a specified ratio. CONSTITUTION:A rare earth element-iron garnet mixed crystal represented by general formula (Y1-xGdx)3Fe5O12 (where 0.1<=x<=0.45) and having <=about 2.7% coefft. of Faraday rotation over the wide temp. range of -50-100 deg.C is formed with Y3Fe5O12 and Gd3Fe5O12. Bi is substituted for part of Re of rare earth element-iron-garnet represented by general formula Re3Fe5O2 to form a mixed crystal (Y1-(y+z)GdyBiz)betaFe5O12 having Faraday rotation ability increased by one digit, and by adjusting the values (y) and (z) to 0.3<=y<=0.42 and 0.15<=z<= 0.3, the saturation magnetization is reduced. A magnetic and optical element 3 is made of said mixed crystal. Thus, an optical isolator composed of polarizing prisms 1, 2, the element 3 and a permanent magnet 4 is obtd. |
