Sm Addition to GdCo and TbFe Films for Magneto-Optical Memory
Introduction In order to improve the magnetic properties of rare earthtransition metal alloys being studied for magneto-optical memory media, we added Sm to GdTbFeCo (a quaternary alloy), to make a quinternary alloy. We already reported that both the Kerr rotation angle and the magnetic anisotropy increase with the addition of Sm [1]. In order to study the origin of these improvements, we added Sm to GdCo and TbFe (each a binary alloy) to make ternary alloys. We then investigated their magnetic and magneto-optical properties.
The thermo-magnetic writing and erasing properties and Kerr rotation angle of amorphous TbFe thin film
The compositional dependences of writing, erasing and reading properties of amorphous TbFe thin film were examined in detail. As a result, there was marked differences between Fe-rich and Tb-rich film. That is, the external magnetic field necessary for writing was generally weaker and less dependent on composition in Tb-rich film and the composition range where erasing could be performed by the field of the same intensity as in writing was wider in Tb-rich side. Kerr rotation angle was measured in two different methods and the scattering values between them were observed in Fe-rich film, while there was no significant difference in Tb-rich film. The origins of these compositional dependence were explained by the differences of temperature dependences of M s and H c besides the compositional dependences of rectangular ratio and M s itself. The effects of the adding third elements to TbFe in Kerr rotation angle and minimum writing laser power were also measured. As a result, it was found, among some elements examined in this study, that Sm had effects of not only decreasing writing power but also increasing Kerr rotation angle in some degree.
Complications of motility peg placement for porous hydroxyapatite orbital implants
Aim: To evaluate the complications associated with pegging of porous hydroxyapatite orbital implants. Methods: Complications associated with pegging were retrospectively reviewed from the charts of 100 of 133 patients with hydroxyapatite implantation from 1993 to 2000. Results: 48 (48%) of the 100 hydroxyapatite implanted patients who had undergone pegging were found to have problems with their pegs, including discharge (45.8%), peg falling out (20.8%), pyogenic granulomas (16.7%), popping peg (14.6%), hydroxyapatite visible around peg hole (8.3%), part of peg shaft visible (6.2%), peg drilled off centre (6.2%), peg drilled at an angle (4.2%), and excess movement of peg (4.2%). The standard peg fell out statistically more often than the peg and sleeve system (Yates's corrected χ2, p=0.038). There was a trend towards complications of the peg with use of a standard peg (versus sleeved peg) (p=0.226). Conclusions: There are several potential complications of pegging. Most complications are minor and can be managed successfully.