Epitaxial growth of Fe3Si/CaF2/Fe3Si magnetic tunnel junction structures on CaF2/Si(111) by molecular beam epitaxy

The Fe3Si(24 nm)/CaF2(2 nm)/Fe3Si(12 nm) magnetic tunnel junction (MTJ) structures were grown epitaxially on CaF2/Si(111) by molecular beam epitaxy (MBE). The 12-nm-thick Fe3Si underlayer was grown epitaxially on CaF2/Si(111) at approximately 400 °C; however, the surface of the Fe3Si film was very rough, and thus a lot of pinholes are considered to exist in the 2-nm-thick CaF2 barrier layer. The average roughness (Ra) of the CaF2 barrier layer was 7.8 nm. This problem was overcome by low-temperature deposition of Fe and Si at 80 °C on CaF2/Si(111), followed by annealing at 250 °C for 30 min to form the Fe3Si layer. The Ra roughness was significantly reduced down to approximately 0.26 nm. A hysteresis loop with coercive field Hc of approximately 25 Oe was obtained in the magnetic field dependence of Kerr rotation at room temperature (RT)

Enhanced Kerr rotation in electrodeposited nickel films

status: publishe

Reactive ion etching of NiFe thin films from first-principles study: A case study

We propose a reactive ion etching (RIE) process design from first-principles calculations for implementation to NiFe thin-film etching. We consider the interaction between the magnetic metal surface NiFe and various gases. We found that the gases CO/NH3, or CH3OH/O 2(/NH3,H2) enable the NiFe surface to be etched. © 2005 The Japan Society of Applied Physics

Studies on Respiration Characteristics of Some Tropical Fruits Grown on Okinawa (Department of Bioproduction)

沖縄県産熱帯果実の代謝生理を知るために3種類の果実について温度と呼吸量の関係を測定したところ, 以下のことが明らかとなった。1)呼吸量の温度依存式としてArrhenius式及びGore式を用いて解析した結果, 測定値は両式によく一致した。2)呼吸量は完熟で果皮が薄く貯蔵力の弱いマンゴ, 7分熟で果皮が薄いパパイヤ, 完熟で果皮の厚いパインアップルの順に高かった。3)生理障害が生じたと推定される温度は完熟パインアップルは9.4℃, 完熟マンゴは7.6℃, パパイヤは11.0℃であった。4) Q_値はパインアップル, マンゴでは低温域で高く, パパイヤでは高温域で高くなった。以上より今回の測定で得られた結果は, 収穫後から貯蔵にいたる果実の代謝生理を容易に知る手段として, 他の果実にも適用でき, 貯蔵装置の設計, 貯蔵中の品質評価を行う上での一つの指標となるものと考えられる。The respiration rate of fresh fruits and vegetables have the fundamental significance in transportation and storage, but there were few data available on respiration of Okinawan grown fruits in wide range of temperatures. In this study, the relationships between respiration rate and temperature of Okinawan grown fruits were measured by carbon dioxide absorption method. Respiration is one of the biochemical reaction, and it is one of chemical reaction velocity. The relationships between respiration rate and temperature were fitted to Arrhenius's equation and Gore's equation (Modified Arrhenius's equation). The respiration heat known as vital heat in kJ per ton per day was obtained multiplying the respiration rate of milligrams of CO_2 per kilogram per hour by a factor of 9.62. Respiration rate of pineapples, mangoes and papayas were measured. It was found that mangoes showed the highest respiration rate, pineapples showed the lowest respiration rate and respiration rate in these tropical fruits were fitted to Arrhenius's equation and Gore's equation and chilling injury estimated zone was assumed 9.4℃ for pineapples, 7.6℃ for mangoes and 11.0℃ for papayas