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C Ihara A Shimatsu H Murabe K Kataoka C Kondo K Nakao 《Canadian Metallurgical Quarterly》1996,19(11):753-757
McCune-Albright syndrome (MAS) is clinically characterized by polyostotic fibrous dysplasia, cafe au lait pigmentation of the skin and multiple endocrinopathies. Recently activating mutations of codon 201 in the gene encoding Gs alpha have been found in affected tissues in MAS. Herein we report a case of acromegaly associated with multiple bone cysts and skin pigmentation in a 47-year-old women. She had suffered a history of aortitis syndrome. The DNA sequence indicated that a Cys201 for Arg201 substitution was found in the GH secreting pituitary adenoma tissue but not in peripheral mononuclear cells. We speculate that the patient has a possible variant from of MAS characterized by multiple bone lesions skin pigmentation and GH-secreting pituitary adenoma. 相似文献
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Shimatsu T. Kondo T. Mitsuzuka K. Watanabe S. Aoi H. Muraoka H. Nakamura Y. 《IEEE transactions on magnetics》2007,43(6):2091-2093
The switching field distributions (SFD) of CoPtCr-SiO2 perpendicular media as a function of Pt content were characterized by subtracting the effect of thermal agitation, and discussed in relation to the microstructure. DC demagnetizing (DCD) magnetization curves and minor dc demagnetizing (M-DCD) magnetization curves were measured at applied field sweep rates of ~10 Oe/s and ~108 Oe/s. We estimated the width of SFD, DeltaSFD, from the difference between the DCD and M-DCD curves, and defined them as DeltaHr/Hr (at ~ 10 Oe/s) and DeltaHr P/Hr P (at ~108 Oe/s). The values of DeltaSFD characterized by subtracting the effect of thermal agitation, DeltaH 0/H0, were nearly half those of DeltaHr /Hr for 10-nm-thick media. DeltaH0/H0 was about 0.10 at 10 at%Pt content, and increased as the Pt content increased, reaching 0.17 at 30 at%Pt content. The increase in DeltaH0/H0 was probably caused by an increase in the stacking fault density and the formation of fcc layers in the hcp CoPtCr lattice. A simple calculation based on the coherent switching of magnetization revealed that the c-axis distribution results in DeltaH 0/H0 of about 0.08, independent of Pt content. These results suggest that the DeltaSFD due to the grain-to-grain anisotropy field variation was small, only 0.02-0.03 相似文献
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Mitsuzuka K. Kikuchi N. Shimatsu T. Kitakami O. Aoi H. Muraoka H. Lodder J.C. 《IEEE transactions on magnetics》2006,42(12):3883-3885
The magnetic properties of dot arrays made of CoPt/Ru perpendicular films (20 nm thickness) were examined as a function of Pt content. The CoPt dot arrays with a dot size D of 140 nm showed a single domain state, after removal of the applied field equal to Hr. Hr decreased from 5.2 kOe to 3.0 kOe as the Pt content decreased from 20 at% to 14 at%. The angular dependence of Hr for these dot arrays indicated coherent rotation of the magnetization during nucleation. The effective magnetic anisotropy, including the demagnetizing energy due to the dot shape, Ku eff, decreased as the Pt content decreased, resulting in the Hr reduction. The values of the switching volume for nucleation, Vsw , evaluated from the stabilizing energy barrier E0, were a few percent of the dot volume. The switching diameter for nucleation, Dsw, increased slightly as the Pt content decreased, which was qualitatively in good agreement with the increase in the exchange length of magnetization. The value of E0/k BT (kB is the Boltzmann constant and T is the absolute temperature) reduced as the Pt content decreased; however, E 0/kBT still had a high of 440 even at 14 at% Pt content. We successfully demonstrated the reduction of Hr for CoPt/Ru patterned films on reducing the Pt content, while simultaneously maintaining a high thermal stability. A calculation based on the experimental results suggested the potential recording density of CoPt/Ru dot arrays used for patterned media to be over 1 Tb/in2 相似文献
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Shimatsu T. Sato H. Oikawa T. Inaba Y. Kitakami O. Okamoto S. Aoi H. Muraoka H. Nakamura Y. 《IEEE transactions on magnetics》2005,41(2):566-571
The magnetic anisotropy of CoPtCr-SiO/sub 2/ perpendicular recording media, including higher energy terms, was studied as a function of film composition and seed layer materials. All series of CoPtCr films with various Cr content, deposited on Ru seed layers, show maximum values of total anisotropy K/sub u/ at 25-30 at%Pt. The maximum value for CoPt(Cr=0) films reaches /spl sim/15/spl times/10/sup 6/ erg/cm/sup 3/. The addition of SiO/sub 2/ to the CoPtCr films reduces the grain K/sub u/, however the grain K/sub u/ maintains a large value of 8/spl times/10/sup 6/ erg/cm/sup 3/ even when 10at%SiO/sub 2/ is added to (Co/sub 90/Cr/sub 10/)/sub 80/Pt/sub 20/, for instance, which indicates the high-potential thermal stability. Theoretical calculations for media designs of 400 Gbits/in/sup 2/ revealed that the ratio of the high-energy anisotropy term K/sub u2/ to K/sub u1/(K/sub u/=K/sub u1/+K/sub u2/) is required to be 0.2-0.35 to enhance the energy barrier for the remanent state, without a notable change in switching field. The films deposited on Ru seed layers were found to show negligibly small K/sub u2/ values, however, the values of K/sub u1/ and K/sub u2/ vary significantly with the seed layer material used. K/sub u1/ decreases almost linearly as the K/sub u2/ value increases. It is concluded that CoPtCr films have a sufficient potential in the values of K/sub u1/ and K/sub u2/ for high-density perpendicular media. 相似文献
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Shimatsu T. Inaba Y. Watanabe S. Kitakami O. Okamoto S. Aoi H. Muraoka H. Nakamura Y. 《IEEE transactions on magnetics》2007,43(6):2103-2105
The magnetic properties and recording performance of hard/soft stacked media consisting of a magnetically hard 9-nm-thick (Co-Pt)-SiO 2 layer underneath a thin (2-3 nm) soft granular layer were studied. Experimental results indicated that an increase in the mean value of saturation magnetization of the soft layer langMs softrang was very effective at improving the recording resolution D50 due to an increase in the slope of magnetization curve alpha. The use of a Co-SiO2 layer, which has the highest langMs softrang in the present study, resulted in the highest D50 value. It is likely that the increase in alpha was mainly caused by the demagnetization field in grains due to the difference between langM s softrang and the mean value of saturation magnetization of the hard layer, langMs hardrang. Moreover, it was successfully demonstrated that the magnetization reversal of (Co-Pt)-SiO2/Co-SiO2 stacked media changed systematically as theoretically predicted on reducing the interfacial exchange coupling by using NiFeCr-SiO2 or Pt-SiO2 interlayers. The reduction of remanence coercivity Hr was achieved by controlling the thickness and film composition of the interlayer, moreover, a high-langMs softrang enhanced the Hr reduction. The Hr reduction improved recording writability without degrading D50, the signal to medium noise ratio SNmR and thermal stability 相似文献
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