Revealing the nanostructure of calcium phosphate coatings using HRTEM/FIB techniques

Journal Article · Thu Dec 15 00:00:00 EST 2016 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.10.035· OSTI ID:22689673

Rodríguez-González, B. ^[1]; Aguiar, H.; Rodríguez-Valencia, C.; Serra, J.; González, P. ^[2]

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1. Servicio de Microscopía Electrónica, CACTI, University of Vigo, Campus As Lagoas-Marcosende, 36310 Vigo (Spain)
2. Applied Physics Department, School of Industrial Engineering, University of Vigo, Campus As Lagoas-Marcosende, 36310 Vigo (Spain)

Herein, we report on the micro- and nanostructure of the calcium phosphate coating produced by pulsed laser deposition (PLD), using focused ion beam (FIB) lamella sample preparation and transmission electron microscopy (TEM) as the characterization technique. The initial selected area electron diffraction (SAED) data demonstrated the presence of hydroxyapatite (HA) over any other possible calcium phosphate crystalline structure and the polycrystalline nature of the coating. Moreover, the SAED analyses showed clear textured ring patterns coherent with the presence of a preferred orientation in the HA nano-crystal growth. The SAED data also indicated that the coating appears to be textured in the 〈002〉 crystalline direction. Dark-field images obtained using 002 as the working reflection showed a clear oriented crystal growth in columns, from bottom to top. These columns have a peculiar arrangement of nano-crystals since, in some cases, the preferred orientation appears to start at a certain distance from the substrate. Direct d-spacing measurements on high-resolution TEM images provided further proof of the presence of an HA nano-crystal structure. The reported data may be of interest in the future to adjust the microstructure of the HA coatings. - Highlights: •The FIB lift-out technique allows a very site-specific sample preparation method for HRTEM analysis. •It also permits a fast assessment of the HA coating thickness and elemental composition (EDS). •The coatings exhibit a nano-crystalline nature, with a texturing effect along the 002 planes. •PLD is suitable for the production of crystalline c-axis oriented hydroxyapatite coatings. •The crystalline HA phase in the PLD coating is very similar to the present in bone.

• OSTI ID: 22689673
• Journal Information: Materials Characterization, Vol. 122; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APATITES
CALCIUM PHOSPHATES
COATINGS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
ELECTRON DIFFRACTION
ENERGY BEAM DEPOSITION
GRAIN ORIENTATION
IMAGES
ION BEAMS
LASER RADIATION
NANOSTRUCTURES
POLYCRYSTALS
PULSED IRRADIATION
RESOLUTION
SAMPLE PREPARATION
SUBSTRATES
THICKNESS
TRANSMISSION ELECTRON MICROSCOPY