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.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics