Toshio Shima

Polishing of YBa2Cu3O7−y by He‐ion etching

Clean polishing is performed by helium‐ion etching on a surface of high‐Tc YBa2Cu3O7−y. Based on a knock‐on cascade model, the decrease of surface roughness is discussed. A rate process of etching is applied for the surface roughness of the high‐Tc YBa2Cu3O7−y.

Ion milling of liquid-quenched glasses

Abstract The effects of cooling rate R and composition of cobalt X on the ion milling rate R in liquid-quenched CoFeSiB alloy glasses are investigated. High cobalt content and low cooling rate enhances R s .

Dependence of the ion milling rate of liquid-quenched stainless steel on the cooling condition

Abstract The dependence of the ion milling rate Rs on the cooling condition was investigated for liquid-quenched 18-8 stainless steel. The higher the cooling rate (the thinner the sample), the lower Rs becomes. Thus, defects are assumed to absorb the kinetic energy for sputtering.

Change in wettability of water on Si after ion treatment by aging under water and in air

Abstract An argon ion sputtering increases the wettability of Si surface. The aging at 300 K decreases the wettability. The wettability decrease is larger when aging is performed in water than when performed in air.

HighT c of YBa2Cu3O x implanted N2

N 2 implantation increases T c under low acceleration energy for high T c YBa 2 Cu 3 O x . The maximum value of T coff is shown at 500 sec of the implantation time. The influence of the current density on T coff is obtained. T coff of the implanted sample above 5 mA mm −2 of the current density remarkably approaches that before the implantation. The maximum T coff value and its increase by N 2 implantation are 96.8 K and 4.1 K at 5×10 −3 mA mm −2 of the detectable minimum current density

Aging induced high Tc of Ar ion-implanted YBa2Cu3O7−y

Abstract Since excess Ar ion-implantation tremendously decreases T c , a recovering process is investigated for high T c YBa 2 Cu 3 O 7 − y .Aging recovers T c of the excess implanted specimens. It is especially that T c increases beyond the value before implantation. Th maximum increased value of the offset temperature is 3.3 K. Excess aging decreases T c . The T c value of the recovered sample approaches that before the implantation. The apparent activation energy of the recovered process is 121 kJ/mole. It approximately agrees with the activation energy of the oxygen diffusivity in YBa 2 Cu 3 O 7− y .

Critical etching time to maintain high T c of Bi-oxide

An influence of the argon-ion etching on Tc is investigated for high-Tc Bi1.6Pb0.4Sr2Ca2Cu3Ox. The etching doesn’t decrease the Tc for 7.0 ks. However, excess etching greatly decreases the Tc. Thus, a critical etching time (te C) to maintain high Tc above 100 K is defined and determined. The te C is 8.5 ks for the argon-ion etching.

AGING INDUCED HIGH T C OF EXCESS ETCHED Bi-Pb-Sr-Ca-Cu-O BY He ION

Ion etching is able to form fragile materials without fracture under clean atmosphere. However, the excess etching decreases the T C value tremendously. Thus, we have started the present study to recover the T C mid value of excess etched Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O x . Aging at room temperature recovers the T C value.

POLISHING OF Bi-Pb-Sr-Ca-Cu-O BY He ION ETCHING

Clean polishing is found. It is performed by helium-ion etching on a surface of high-T C Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O x . Based on a knock-on cascade model, the decrease of surface roughness is discussed.

RAPID RATE OF He ION ETCHING RATE OF HIGH T C Bi-Pb-Sr-Ca-Cu-O

A high helium-ion etching rate is observed for the high T C Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O x . The high etching rate (R s ) is found at high angles of incidence (θ) of the ion-beam and at short etching times.