Pulsed laser ablation deposition of yttrium iron garnet and cerium-substituted YIG films

Yttrium iron garnet (YIG) thin films were grown on gadolinium gallium garnet substrates using pulsed laser ablation deposition (PLAD) with a XeCl excimer laser. Films were grown up to over 2 μm thick, however cracking proved to be a problem for films over 1 μm thick. The lattice parameter(s) of the films and the substrates were measured and indicated that the film/substrate structure was bending to accommodate strain due to the lattice mismatch. The films had saturation magnetisation values close to that of bulk YIG and were isotropic in the film plane. The magnetisation data also indicate stress-induced uniaxial isotropy. The ablation conditions were varied to produce uncracked films with low droplet densities. YIG melts incongruently during the laser ablation process and cone-like structures form on the ablation target lowering the ablation rates. Cerium-substituted YIG films were also grown in both oxygen and argon atmospheres, substituting cerium into YIG increases the lattice parameter and hence reduces the strain. The Ce-YIG film grown in argon was greenish indicating that cerium was in the desired oxidation state.

[1]  J. Coey,et al.  Magnetism and Magnetic Materials , 2001 .

[2]  R. Ramesh,et al.  Epitaxial Magnetic Garnet Thin Films and Heterostructures by Pulsed Laser Deposition , 1994 .

[3]  J. Adam,et al.  Thick yttrium-iron-garnet (YIG) films produced by pulsed laser deposition (PLD) for integration applications , 1995 .

[4]  J. Santiago-Avilés,et al.  Surface compositional and topographical changes resulting from excimer laser impacting on YBa2Cu3O7 single phase superconductors , 1988 .

[5]  G. A. Prinz,et al.  Science and Technology of Nanostructured Magnetic Materials: Proceedings of a NATO Advanced Study Institute Conference Held in Aghia Pelaghia, Crete, Greece on 24 June -6 July 1990. NATO ASI Series B: Physics. Volume 259 , 1990 .

[6]  H. Rogalla,et al.  High-Tc thin films prepared by laser ablation: material distribution and droplet problem , 1992 .

[7]  D. Krajnovich,et al.  Formation of ‘‘intrinsic’’ surface defects during 248 nm photoablation of polyimide , 1993 .

[8]  M. Kakihana,et al.  Materials Research Society Symposium - Proceedings , 2000 .

[9]  S. Palmer,et al.  Design of an elegant and inexpensive multiple target holder and laser beam scanner for use in laser-ablation deposition of thin films , 1995 .

[10]  A. Tate,et al.  Structure and Lattice Deformation of Ce-Substituted Yttrium Iron Garnet Film Prepared by RF Sputtering , 1993 .

[11]  A. Tate,et al.  Crystallinity of Ce Substituted YIG Films Prepared by RF Sputtering , 1996 .

[12]  M. Abe,et al.  Giant Faraday Rotation of Ce-Substituted YIG Films Epitaxially Grown by RF Sputtering , 1988 .

[13]  Toshihiro Shintaku,et al.  Ce-substituted yttrium iron garnet films prepared on Gd3Sc2Ga3O12 garnet substrates by sputter epitaxy , 1997 .

[14]  C. Vittoria,et al.  Epitaxial yttrium iron garnet films grown by pulsed laser deposition , 1993 .

[15]  K. L. Chopra,et al.  Thin Film Phenomena , 1969 .

[16]  Xindi Wu,et al.  Target modification in the excimer laser deposition of YBa2Cu3O7−x thin films , 1991 .