Abstract: The present invention relates to a magnetic garnet single crystal and a Faraday rotator using the magnetic garnet single crystal and the object of the present invention is to provide a magnetic garnet single crystal which suppresses a generation of crystal defects and a Faraday rotator which improves an extinction ratio. A magnetic garnet single crystal grown by a liquid-phase epitaxial growth method and having the general formula represented by BiaPbbA3−a−bFe5−c−dBcPtdO12 is used, wherein A is at least one kind of element selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, B is at least one kind of element selected from Ga, Al, Sc, Ge and Si, and a, b, c and d are represented by 0.8<a<1.4, 0<b≦20, 0≦c≦0.9 and 0<d≦2.0 respectively.

Abstract: An object is to provide a magnetic garnet material, even if a thickness of an element is made thin, in which a sufficient Faraday rotation capacity can be obtained, a magnetic field for saturation can be controlled to be less than 200 (Oe), and a magnetic compensation temperature can be controlled to be less than 0° C. as well as to provide a Faraday rotator which can be made thin, suppresses a manufacturing cost and achieves a high yielding. The above object can be achieved by a magnetic garnet material known as the general chemical formula BixYbyGdzM13-x-y-zFewM2uM35-w-uO12 and the Faraday rotator using the above material. However, M1 is more than one kind of chemical elements which can replace Bi, Yb or Gd, M2 is more than one kind of non-magnetic chemical elements which can replace Fe, and M3 is more than one kind of chemical elements which can replace Fe and M2. Further, x, y, z, w and u respectively satisfies 1.0≦x≦1.6, 0.3≦y≦0.7, 0.9≦z≦1.6, 4.0≦w≦4.3 and 0.7≦u≦1.0.