Thermal stability of information storage tapes prepared from very fine metal particles

Effect of orientation on the thermal stability in advanced metal particulate tapes

“…6 and 7 in the range from 0.2 to 1.2 kOe. 4,8 However, V act of an assembly of ultrafine particles is believed to be not a value of V phy . For each data recording tape series, the values of X tot and X rev decreased as OR increased in the reverse field of approximately 1.1 kOe or less.…”

“…In isotropic tapes ͑OR= 1.00͒, the values of X tot and X rev of A-1 tape ͑V phy = 1.7ϫ 10 −18 cm 3 ͒ were much smaller than that of B-1 tape ͑V phy = 5.3ϫ 10 −18 cm 3 ͒ at the same reverse field. 4,5 However, more detailed experimental studies will be necessary to determine the main reasons behind the effects of the distribution of V phy on V act for advanced data recording tapes with very small V phy . Figure 8 shows the reverse field dependence of X irr as obtained from X tot − X rev using the values in Figs.…”

“…4,5,[14][15][16] A saturating field of 20 kOe is applied at the angle = 85°from the direction of easy magnetization ͑ =0°͒, then the direction of the magnetic field is rotated through 10°and the field ͑H n ͒ is applied. 4,5,[14][15][16] A saturating field of 20 kOe is applied at the angle = 85°from the direction of easy magnetization ͑ =0°͒, then the direction of the magnetic field is rotated through 10°and the field ͑H n ͒ is applied.…”

“…[3][4][5] Activation volume ͑V act ͒ is an important factor in determining the thermal stability and media noise of high-density recording media. 1,2 However, the normalized magnetization decay ͓⌬M / ͕M r ͑log t 1 − log t 2 ͖͔͒ due to the thermal fluctuation increases as V phy decreases for advanced data recording tapes prepared from ultrafine particles, where ⌬M is the change in magnetization for the time interval from t 1 to t 2 and M r is the residual magnetization.…”

Correlation of fluctuation field and temperature coefficient of coercivity in a CoCrPtB thin film

“…(1) is a major factor affecting the media noise and recorded signal decay for highdensity recording media [9,10]. V act is expected to be equal to V phy for a magnetically isolated single domain particle, and is the minimum unit volume of magnetization reversal [3,11]. In the case of Co 55 Cr 15.5 Pt 28 B 1.5 /Co 63 Cr 37 /Cr thin films with the smallest V phy , V phy was smaller than V act as shown in Table 1.…”