Universidad Nacional Autónoma de México - CNyN

1st International Symposium on Nanoscience and Nanomaterials
practical interest. The wide range of applications of carbon nano-fibers have been derived from its
characteristics such as high heat resistance, high mechanical strength, inert chemical (corrosion), and
biocompatibility, having a large range of application coverage in general industry to the aerospace and
medicine. In this work we report a novel method to grow carbon nanofibers on Si wafers by Chemical Vapor
Deposition (CVD) in a three-zone horizontal quartz tube reactor. UHP methane (CH 4 ) and UHP hydrogen
(H 2 ) where used as precursors. Methane and hydrogen are introduced in the reactor where they are combined
with ammonia (NH 3 ) at the following conditions: pressure = 22 Torr, temperature at zone 1 = 1200 °C,
temperature at zone 2 = 900 °C and temperature at zone 3 = 520 °C, the flux were CH 4 = 10 sccm, NH 3 = 30
sccm and H 2 = 380 sccm during one hour of deposit. At these conditions the methane discomposes to yield
carbon nanofibers. The fibers obtained were analyzed by XPS, IR, SEM, TEM and XRD. The results
indicated that this novel method can be used to produce large quantities of high quality carbon nano-fibers in
short time and low cost.
P-003
EFFECTS ANNEALING ATMOSPHERE ON STRUCTURAL, OPTICAL AND ELECTRICAL
PROPERTIES OF ZnO THIN FILMS
H. Juárez 1,a , M. Pacio 1 , C. Bueno 1 , R. Perez 1 , G. Juárez 1 , E. Vargas 1 , M. Rodríguez 1 , T. Diaz 1 .
1 CIDS-ICUAP, Benemérita Universidad Autónoma de Puebla, 14 Sur y Av. San Claudio, C.U., Edif. 103C,
C.P. 72750, Pue., Puebla,
Keywords: Zinc Oxide.
1a hjuarez@cs.buap.mx
ZnO films were obtained by the sol-gel method utilizing zinc acetate dihydrate as the precursor of
the Zn atom, monoethanolamine (MEA) as a stabilizing agent and 2-methoxyethanol as a solvent. The ZnO
films were deposited on p-Si substrates via spin-coating technique. The gel film was stabilized by pre-heating
at 300 ºC. This procedure was repeated 10 times. After, the films were crystallized by an annealing at 600 ºC
in Oxygen, Ozone and Nitrogen atmosphere. The optical and structural properties of the ZnO films depend on
the annealing temperature and the atmosphere type. These conditions also affect the properties of the n-
ZnO/p-Si heterostructure. The X-ray diffraction patterns shown that all the films have (002) preferential
orientation and the photoluminescence measurements show emission that corresponding to the UV and visible
region. UV-Vis spectroscopy was used to determine the reflectivity and the band gap of the ZnO films. The
electrical properties were obtained by I-V curves of the n-ZnO/p-Si heterostructure. Finally shows that the
structural, optical and electrical properties have correlation with the annealing atmosphere.
P-004
PORE SIZE DISTRIBUTION IN ZEOLITES WITH RINGS 8, 10 AND 12 PARTS: LTA, ERI, HEU,
ZSM5, MOR, FAU
Vázquez Tobón Olga A. 1,a , Hernández Espinoza Miguel A. 2,b
1 Colegio de Ingeniería en Materiales, Facultad de Ingeniería Química, BUAP; Puebla, México
2 Departamento de Investigación en Zeolitas y Posgrado en Ciencias Ambientales, Instituto de Ciencias,
BUAP; Puebla, México
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