鈷在鉑上形成超尖磁性奈米針尖之研究
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2009
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我們利用場離子顯微鏡在超高真空的環境中觀察兩種磁性奈米針尖的成長，一種是利用表面皺化機制形成的鈷鉑合金金字塔形奈米針尖；另一種是藉由鈷在鉑(111)面的S. K. mode長成以鉑為基底的鈷奈米針尖。前者針尖生長於皺化形成的鈷鉑合金多面體之稜線交接處，分別位於{531}及{210}切面，{531}切面的金字塔是由擴張的{111}、{110}、{311}切面堆積，{210}切面的金字塔則由擴張的{110}及兩個{311}切面組成。而後者針尖是在室溫及20K時鍍鈷4～5ML於鉑(111)面，鈷原子先依鉑基底以FCC結構排列，再於其上堆積單顆、雙顆或三顆原子團，這些在鉑(111)面成長的鈷原子團即是一種無特定針形的奈米針尖。
The formation of two magnetic nano tips are studied with a UHV field ion microscope. One is a PtCo pyramidal tip formed by surface faceting、the other is a Pt based Co tip followed the S. K. growth mode. The former is fabricated on the pyramidal sites of a faceting PtCo polyhedron. Pyramids grown upon {531} consist of {111}、{110} and {311} facets、while the pyramids formed on {210} consist of {110} and {311} facets. In addition、Co atoms are aggregated to 3D islands with FCC structure after 4～5ML Co is deposited on the Pt (111) facet. Occasionally we find single Co atom、dimer or trimer site on Pt (111) facet. These adatoms on Pt (111) facet form another kind of single atom tip.
The formation of two magnetic nano tips are studied with a UHV field ion microscope. One is a PtCo pyramidal tip formed by surface faceting、the other is a Pt based Co tip followed the S. K. growth mode. The former is fabricated on the pyramidal sites of a faceting PtCo polyhedron. Pyramids grown upon {531} consist of {111}、{110} and {311} facets、while the pyramids formed on {210} consist of {110} and {311} facets. In addition、Co atoms are aggregated to 3D islands with FCC structure after 4～5ML Co is deposited on the Pt (111) facet. Occasionally we find single Co atom、dimer or trimer site on Pt (111) facet. These adatoms on Pt (111) facet form another kind of single atom tip.
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奈米針尖, 磁性, 超尖, 鈷, 鉑, 合金, nano tip, magnetic, ultra-sharp, Co, Pt, alloy