Activation volumes in CoPtCr-SiO2 perpendicular recording media

CoPtCr-SiO2 perpendicular recording media with varying levels of SiO2 were examined by two different methods to determine the activation volume. The first is based on the sweep-rate dependence of the remanence coercivity using Sharrock's equation. The second is based on the measurement of the fluctuation field from time-dependence data, determined using a magneto-optical Kerr effect (MOKE) magnetometer. The values of V-act measured at the coercivity for both methods are almost the same, with the fluctuation field and activation volumes increasing with the SiO2 content. The difference between V-act and the grain volume measured directly from bright-field TEM images decreases as the SiO2 content increases due to the reduction of intergranular exchange coupling. The experimental results indicate that values of V-act obtained from single- and double-layered media are consistent. It was also found that the coercivity and normalized hysteresis loop slope at coercivity varied with SiO2 content, with the coercivity peaking at 8 at % SiO2 (nearly 26 vol% SiO2)

Thermal fluctuation of magnetization in nanocrystalline FePt thin films with high coercivity

科研費報告書収録論文(課題番号:11305027・基盤研究(A)(2)・H11～H12/研究代表者:中村, 慶久/柔軟なスピンクラスター配列からなる超高密度磁気記録メディアの研究

Thermal agitation of magnetization in CoCrPt perpendicular recording media

科研費報告書収録論文(課題番号:11305027・基盤研究(A)(2)・H11～H12/研究代表者:中村, 慶久/柔軟なスピンクラスター配列からなる超高密度磁気記録メディアの研究

Sustainable resorts: Learning from the 2004 tsunami

Purpose - Given the extensive destruction resulting from the devastating 2004 Indian Ocean tsunami that destroyed and damaged resort complexes in southern Thailand, the purpose of this research paper is to focus on the planning of architecture of resorts in two layers: the relationship of structures and land use to the natural environment, and the identification of specific design flaws that resulted in the loss of life. Design/methodology/ approach - An international collaborative effort led to site visits by our research team to the hardest-hit resort areas of Khao Lak, Takua Pa, and Ko Phi Phi on December 29, 2004-January 6, 2005, and in February 2005. The research team had direct contact with the adverse effects of the tsunami and gained insightful understanding on how structures and faulty architectural designs worsened the disaster and obstructed the process of saving lives. Analysis of these effects were then compiled and used to underpin subsequent proposals for resort reconstruction to minimize future destruction which may result from such calamities. Findings - Close scrutiny and subsequent analysis of various factors which magnified the destruction and damage caused by the tsunami resulted in action plan proposals for sustainable resort development aimed at avoiding a repeat of the tragedy. These include responses to site, architecture, structures, building services and landscaping. More specifically proposals were made on issues of relocation, modifications of design flaws, introduction of escape routes, safer rooms, restoration of waterways, co-generation, tree plantation and incorporation of natural landscape. Research limitations/ implications - Most of the information and data were gathered first hand at the location mentioned. More studies are needed to reinforce and further validate the proposed measures as generally applicable in similar locations. Originality/value - An action plan outlining measures aimed at minimizing damage from such natural disasters could provide a useful resource in future planning of resorts in tsunami prone locations. © Emerald Group Publishing Limited.published_or_final_versio

Induced uniaxial magnetic anisotropy field in very thin NiFe and CoZrNb films

科研費報告書収録論文(課題番号:11305027・基盤研究(A)(2)・H11～H12/研究代表者:中村, 慶久/柔軟なスピンクラスター配列からなる超高密度磁気記録メディアの研究

Effect of a Ti seed layer on the magnetic properties of CoCrTa double-layered perpendicular media

科研費報告書収録論文(課題番号:11305027・基盤研究(A)(2)・H11～H12/研究代表者:中村, 慶久/柔軟なスピンクラスター配列からなる超高密度磁気記録メディアの研究

Recording performance of CoCrPt-(Ta, B)/TiCr perpendicular recording media

科研費報告書収録論文(課題番号:11305027・基盤研究(A)(2)・H11～H12/研究代表者:中村, 慶久/柔軟なスピンクラスター配列からなる超高密度磁気記録メディアの研究