Crystal defects in epitaxial InP layers: electrical and scanning electron microscope study

Electrical characteristics of p-type Au/lnP Schottky junctions with Pt nanoparticles sandwiched in epitaxial layer have been studied and compared with reference samples. Various anomalies have been obtained, some of them are similar to the behavior of quantum dot structures. However, it is concluded that the obtained electrical anomalies are connected with pinhole-like defects originated from the break of the epitaxial layer during preparation.Исследованы электрические характеристики переходов Шоттки в Au/lnP p-типа с наночастицами Pt, введенными в эпитаксиальный слой; результаты сопоставлены с характеристиками образцов сравнения. Обнаружены различные аномалии, некоторые из них аналогичны поведению структур квантовых точек. Сделан, однако, вывод, что наблюдаемые аномалии связаны с дефектами точечного типа, обусловленными разрывами эпитаксиального слоя в процессе его нанесения.Досліджєно єлєктричні характеристики пєрєходів Шотткі в Au/lnP p-типу з наночас-тинками Pt, введеними в епітаксійний шар; результати зіставлено з характеристиками зразків порівняння. Виявлено різноманітні аномалії, деякі з них аналогічні поведінці структур квантових точок. Зроблено, однак, висновок, що виявлені аномалії пов’язані з дефектами точкового типу, обумовленими розривами епітаксійного шару в процесі його нанесення

Chemical characterization and anticorrosion properties of corrosion products formed on pure copper in synthetic rainwater of Rio de Janeiro and Sao Paulo

This work aims to characterize corrosion products formed on copper samples exposed to synthetic rainwater of Rio Janeiro and Sao Paulo. XRD and XPS were employed to determine their composition, while electrochemical techniques were used to evaluate their protective properties. XRD and XPS indicated the thickening of the corrosion layer with time. Electrochemical results showed that the protectiveness of the corrosion layer depends on the solution composition. Based on our findings a corrosion mechanism for copper in simulated rainwater is proposed where the role of NH(4)(+) ions in the cuprite layer partial regeneration is taken into account. (C) 2009 Elsevier Ltd. All rights reserved

Chemical characterization and anticorrosion properties of corrosion products formed on pure copper in synthetic rainwater of Rio de Janeiro and Sao Paulo

This work aims to characterize corrosion products formed on copper samples exposed to synthetic rainwater of Rio Janeiro and Sao Paulo. XRD and XPS were employed to determine their composition, while electrochemical techniques were used to evaluate their protective properties. XRD and XPS indicated the thickening of the corrosion layer with time. Electrochemical results showed that the protectiveness of the corrosion layer depends on the solution composition. Based on our findings a corrosion mechanism for copper in simulated rainwater is proposed where the role of NH(4)(+) ions in the cuprite layer partial regeneration is taken into account. (C) 2009 Elsevier Ltd. All rights reserved