<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2007000700008</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Normal modes of vibration of carbon nanotubes doped with nitrogen: towards conducting properties]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Soto]]></surname>
<given-names><![CDATA[J.R]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Austrich]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Valladares]]></surname>
<given-names><![CDATA[R.M]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Valladares]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Marquina]]></surname>
<given-names><![CDATA[M.L]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Espejel]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Calles]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Nacional Autónoma de México Facultad de Ciencias ]]></institution>
<addr-line><![CDATA[México D.F]]></addr-line>
<country>México</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>01</month>
<year>2007</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>01</month>
<year>2007</year>
</pub-date>
<volume>53</volume>
<fpage>34</fpage>
<lpage>36</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2007000700008&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2007000700008&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2007000700008&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[The conducting properties of carbon nanotubes can be changed by nitrogen doping. There exists an enormous interest in modifying the conducting properties of organic and inorganic single and multiwall nanotubes, through doping, since their modified transport properties can be exploited in electronic nano-devices such as diodes, transistors, etc. In this work we study the normal modes of vibration of the armchair (4,4) nanotube: pristine and with nitrogen doping. We used the Density Functional Theory approach including periodic boundary conditions to obtain the ab initio Hessian tensor.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Las propiedades conductoras de los nanotubos de carbon pueden cambiarse si se dopan con impurezas de nitrógeno. Existe un gran interés por modificar las propiedades conductoras de los nanotubos simples y multicapa, orgánicos e inorgánicos, mediante el dopaje, ya que sus propiedades modificadas de transporte pueden aprovecharse en nano-dispositivos electrónicos como diodos, transistores, etc. En este trabajo se estudian los modos normales de vibración del nanotubo armchair (4,4): puro y con impurezas de nitrógeno. Se empleó la aproximación de la Teoría de Funcional de la Densidad, incluyendo condiciones de frontera periódicas, para obtener el tensor Hessiano de primeros principios.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Nanotubes]]></kwd>
<kwd lng="en"><![CDATA[electronic properties]]></kwd>
<kwd lng="en"><![CDATA[nitrogen doping]]></kwd>
<kwd lng="en"><![CDATA[density functional theory]]></kwd>
<kwd lng="es"><![CDATA[Nanotubos]]></kwd>
<kwd lng="es"><![CDATA[propiedades electrónicas]]></kwd>
<kwd lng="es"><![CDATA[dopado con Nitrógeno]]></kwd>
<kwd lng="es"><![CDATA[teoría de funcional de la densidad]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="center"><font face="verdana" size="4"><b>Normal modes of vibration of carbon nanotubes doped with nitrogen: towards conducting properties</b></font></p>     <p align="center"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>J.R. Soto*, J. Austrich, R.M. Valladares, A. Valladares, M.L. Marquina, R. Espejel, and A. Calles</b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><i>Facultad de Ciencias, Universidad Nacional Aut&oacute;noma de M&eacute;xico, Apartado Postal 70&#150;646, 04510 M&eacute;xico D.F., M&eacute;xico.</i></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">Corresponding author:     <br>   Fax (52)5556160326,     <br>   e&#150;mail: <a href="mailto:jr&#150;soto@correo.unam.mx" target="_blank">jr&#150;soto@correo.unam.mx</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">Recibido el 9 de junio de 2006    <br>   Aceptado el 6 de noviembre de 2006</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">The conducting properties of carbon nanotubes can be changed by nitrogen doping. There exists an enormous interest in modifying the conducting properties of organic and inorganic single and multiwall nanotubes, through doping, since their modified transport properties can be exploited in electronic nano&#150;devices such as diodes, transistors, etc. In this work we study the normal modes of vibration of the armchair (4,4) nanotube: pristine and with nitrogen doping. We used the Density Functional Theory approach including periodic boundary conditions to obtain the <i>ab initio </i>Hessian tensor.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords: </b>Nanotubes; electronic properties; nitrogen doping; density functional theory.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">Las propiedades conductoras de los nanotubos de carbon pueden cambiarse si se dopan con impurezas de nitr&oacute;geno. Existe un gran inter&eacute;s por modificar las propiedades conductoras de los nanotubos simples y multicapa, org&aacute;nicos e inorg&aacute;nicos, mediante el dopaje, ya que sus propiedades modificadas de transporte pueden aprovecharse en nano&#150;dispositivos electr&oacute;nicos como diodos, transistores, etc. En este trabajo se estudian los modos normales de vibraci&oacute;n del nanotubo <i>armchair </i>(4,4): puro y con impurezas de nitr&oacute;geno. Se emple&oacute; la aproximaci&oacute;n de la Teor&iacute;a de Funcional de la Densidad, incluyendo condiciones de frontera peri&oacute;dicas, para obtener el tensor Hessiano de primeros principios.</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores: </b>Nanotubos; propiedades electr&oacute;nicas; dopado con Nitr&oacute;geno; teor&iacute;a de funcional de la densidad. </font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">PACS: 73.63.Fg; 78.66.Tr; 71.15.Mb</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmf/v53s1/v53s1a8.pdf">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. S. Ijima, <i>Nature</i> <b>354</b> (1991) 56.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8336469&pid=S0035-001X200700070000800001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">2. R. Czerw <i>et al., Nanoletters </i><b>1</b> (2001) 457.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8336470&pid=S0035-001X200700070000800002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">3. J.P. Perdew, K. Burke, and M. Ernzerhof, <i>Phys. Rev. Lett. </i><b>78</b> (1997) 1396.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8336471&pid=S0035-001X200700070000800003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
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