Spectrochimica Acta Part B: Atomic Spectroscopy
High spatial resolution X-ray microdiffraction applied to biomaterial studies and archeometry☆
Introduction
The high demand of thorough characterization of materials and processes requires development of advanced diagnostic methods. One of the important figures of merit in many cases is the spatial resolution. The X-ray microdiffraction technique combines diffraction, which is a powerful tool for structural analysis, with the high spatial resolution. To this purpose, the X-ray beam must, in general, be conditioned. In principle, a simple pinhole could do this task, but photon flux would be lost. Therefore, focusing X-ray optics must be employed to concentrate photon flux in small dimensions, as lenses do in the visible spectrum. Unfortunately, there are severe problems in fabricating optical elements for hard X-rays capable to reach sub-micrometer spatial resolution. The advent of the high brilliant synchrotron radiation sources gave new impulse to research for innovative X-ray optics. At present, the available optics for hard X-rays are the Fresnel Zone Plates [1] based on diffraction, the refractive lenses [2] based on refraction, the capillaries [3] and curved mirrors [4] based on total reflection and the X-ray waveguides (WGs) [5], [6], [7] based on standing waves which have demonstrated the capability to provide the highest spatial resolution (in one dimension) up to now.
Since the initial experiments using the WG [5], remarkable improvements have been done with respect to optics efficiency [8], and with respect to integration of the optical element in a microdiffraction set-up and to experimental procedures [9], [10]. In this work, we present three recent applications of microdiffraction using the WG in the field of biology and archeometry.
Section snippets
X-ray waveguides
A typical waveguide structure (see Fig. 1) consists (from bottom to top) of an ultra-flat substrate, a metal layer few tens of nm thick, a guiding layer made of a low-density material having a thickness of the order of 100 nm and a metal cap layer a few nm thick. This structure allows the formation of a strong X-ray standing wave (XSW) field inside the guiding layer with the spatial periodicity depending on the incident angle. When the XSW periodicity is equal to an integer fraction of the
Newly formed bone at prosthesis interface
Events leading to the integration of an implant into a bone, determining the performance of the device, take place largely at the tissue/implant interface [10], [11], [12]. After implantation, reactions occur at the tissue/implant interface that lead to time-dependent changes in the tissues and in the surface characteristics of the implant material.
Up to now, the details of the interactions between tissue and implant are still poorly understood being a complex problem. In particular, as it is
Conclusions
In this work, the power of the microdiffraction technique using the waveguide has been shown presenting three examples carried out at the ID13 beamline of ESRF regarding different scientific fields. Mainly in the cases of bone formation, the high spatial resolution provides unique information on regions with very high gradients in physical quantities, as in the case of interfaces.
In particular, the first two examples regarded the local structural analysis of the newly formed bone and the
Acknowledgement
It is a pleasure to thank Dr. N.N. Aldini and Prof. R. Giardino who provide the thin sections of the samples with the coated and uncoated orthopaedic devices.
This work was partially supported by the program PURS of the National Institute for the Physics of Matter (INFM).
References (23)
- et al.
Nucl. Instrum. Methods, A
(1992) - et al.
Biomaterials
(1999) - et al.
- et al.
Nature
(1996) - et al.
J. Opt. Soc. Am.
(1948) - et al.
J. Appl. Phys.
(1996) - et al.
Appl. Phys. Lett.
(1995) - et al.
J. Appl. Phys.
(1996) - et al.
Appl. Phys. Lett.
(2001) - et al.
Nature
(2000)
Phys. Med. Biol.
Cited by (11)
Analysis of bone response to dental bone grafts by advanced physical techniques
2017, Bone Response to Dental Implant MaterialsSome applications of nanotechnologies in stem cells research
2009, Materials Science and Engineering: BBulk and interface investigations of scaffolds and tissue-engineered bones by X-ray microtomography and X-ray microdiffraction
2007, BiomaterialsCitation Excerpt :Indeed, the chemistry and the geometry of the scaffold used to deliver osteogenic cells in the lesion site determine the spatial organization of the new bone and the bone–biomaterial integration. In this regard [78,79,84] an advanced experimental method was recently proposed based on the simultaneous acquisition of WAXS and SAXS performed by means of focusing optics and an X-ray waveguide, which allows a local analysis with sub-micrometer spatial resolution. Several thin sections of different engineered bone samples were analyzed and similar results were obtained for all samples; only the significant results of one sample are reported here.
Archaeometallurgy using synchrotron radiation: A review
2012, Reports on Progress in PhysicsAdvanced Nanoscale Characterization of Cement Based Materials Using X-Ray Synchrotron Radiation: A Review
2013, International Journal of Concrete Structures and MaterialsApplication of microfocus x-ray beams from synchrotrons in heritage conservation
2012, International Journal of Architectural Heritage
- ☆
This paper was presented at the International Congress on X-Ray Optics and Microanalysis (ICXOM XVII), held in Chamonix, Mont Blanc, France, 22–26 September 2003, and is published in the special issue of Spectrochimica Acta Part B, dedicated to that conference.