The Mayo-Darley massif is an anorogenic complex of the Cameroon Line that has a mantle origin.Tin-bearing rocks were analyzed by ICP-AES and INAA analytical methods.The purpose of this work was to provide new geochemi...The Mayo-Darley massif is an anorogenic complex of the Cameroon Line that has a mantle origin.Tin-bearing rocks were analyzed by ICP-AES and INAA analytical methods.The purpose of this work was to provide new geochemical data for the Mayo-Darley tin formation and to understand its petrogenesis and the origin of tin mineralization.The Mayo-Darley tin deposit is made up of tin-granite,and tin-greisen,greisenification was developed on the borders of quartz dykes.These rocks belong to the alkaline series and were classified into acid(SiO2-=61.6%–73.8%;65.4%–98%respectively)and basic(42.9%–47%SiO_(2))rocks.They showed enrichment in HSFE,LILE,Ga/Al and chondrite normalized REE patterns indicating LREE enrichment relative to HREE with a negative Eu anomaly,only sample SB8 of tin-granite showed Eu/Eu*=1.11.Rocks display metaluminous,peralkaline,peraluminous,ferroan,high-K calc-alkaline to shoshonitic,alkalic to calcic affinity,and crystallized at800°C.The chemistry of this deposit reflects the primary composition of granite,quartz monzonite,gabbro,and foid gabbro.This complex experienced multi-stage sub-solidus hydrothermal fluid reactions and shows variable alteration of feldspars alkali mobility.The rocks are classified as A1-type granite,overlap with the OIB field,and were derived from a within-plate setting,similar to mantle non plumederived magmas.The origin of tin mineralization in MayoDarley has a complex evolution,tin mineralization was derived from hydrothermal and hydrogenous metal-rich deposits and shows Sn–Hf–Zr and Sn–Tl–Nb association.These new data confirm the complexity of the Mayo-Darley tin complex and elucidate the origin of tin mineralization.展开更多
With the continued downscaling of complementary metal-oxide-semiconductor field effect transistor dimensions, high-dielectric constant （high-k） gate materials, as alternatives to SiO2, have been extensively investig...With the continued downscaling of complementary metal-oxide-semiconductor field effect transistor dimensions, high-dielectric constant （high-k） gate materials, as alternatives to SiO2, have been extensively investigated. Hf （Zr）-based high-k gate dielectric thin films have been regarded as the most promising candidates for high-k gate dielectric according to the International Technology Roadmap for Semiconductor due to their excellent physical properties and performance. This paper reviews the recent progress on Hf （Zr）-based high-k gate dielectrics based on PVD （physical vapor deposition） process. This article begins with a survey of various methods developed for generating Hf （Zr）-based high-k gate dielectrics, and then mainly focuses on microstructure, synthesis, characterization, formation mechanisms of interfacial layer, and optical properties of Hf （Zr）-based high-k gate dielectrics. Finally, this review concludes with personal perspectives towards future research on Hf （Zr）-based high-k gate dielectrics.展开更多
文摘The Mayo-Darley massif is an anorogenic complex of the Cameroon Line that has a mantle origin.Tin-bearing rocks were analyzed by ICP-AES and INAA analytical methods.The purpose of this work was to provide new geochemical data for the Mayo-Darley tin formation and to understand its petrogenesis and the origin of tin mineralization.The Mayo-Darley tin deposit is made up of tin-granite,and tin-greisen,greisenification was developed on the borders of quartz dykes.These rocks belong to the alkaline series and were classified into acid(SiO2-=61.6%–73.8%;65.4%–98%respectively)and basic(42.9%–47%SiO_(2))rocks.They showed enrichment in HSFE,LILE,Ga/Al and chondrite normalized REE patterns indicating LREE enrichment relative to HREE with a negative Eu anomaly,only sample SB8 of tin-granite showed Eu/Eu*=1.11.Rocks display metaluminous,peralkaline,peraluminous,ferroan,high-K calc-alkaline to shoshonitic,alkalic to calcic affinity,and crystallized at800°C.The chemistry of this deposit reflects the primary composition of granite,quartz monzonite,gabbro,and foid gabbro.This complex experienced multi-stage sub-solidus hydrothermal fluid reactions and shows variable alteration of feldspars alkali mobility.The rocks are classified as A1-type granite,overlap with the OIB field,and were derived from a within-plate setting,similar to mantle non plumederived magmas.The origin of tin mineralization in MayoDarley has a complex evolution,tin mineralization was derived from hydrothermal and hydrogenous metal-rich deposits and shows Sn–Hf–Zr and Sn–Tl–Nb association.These new data confirm the complexity of the Mayo-Darley tin complex and elucidate the origin of tin mineralization.
基金the support from the National Major Project of Fundamental Research:Nanomaterials and Nanostructures(Grant No.2005CB623603)the National Natural Science Foundation of China(Grant No.10674138)the Special Fund for President Scholarship,Chinese Academy of Sciences.
文摘With the continued downscaling of complementary metal-oxide-semiconductor field effect transistor dimensions, high-dielectric constant （high-k） gate materials, as alternatives to SiO2, have been extensively investigated. Hf （Zr）-based high-k gate dielectric thin films have been regarded as the most promising candidates for high-k gate dielectric according to the International Technology Roadmap for Semiconductor due to their excellent physical properties and performance. This paper reviews the recent progress on Hf （Zr）-based high-k gate dielectrics based on PVD （physical vapor deposition） process. This article begins with a survey of various methods developed for generating Hf （Zr）-based high-k gate dielectrics, and then mainly focuses on microstructure, synthesis, characterization, formation mechanisms of interfacial layer, and optical properties of Hf （Zr）-based high-k gate dielectrics. Finally, this review concludes with personal perspectives towards future research on Hf （Zr）-based high-k gate dielectrics.
