For the precise characterization of gauge-blockshaped measuring objects made of high tech materials, a precision interferometer was developed with the aim of measuring samples of up to 400 mm length with uncertainties in the sub-nanometer range. From such exact measurements of length, it is possible to calculate the thermal expansion coefficient as a function of the temperature with uncertainties of up to 2 • 10–10 • K–1. Furthermore, it is possible to get quantitative statements regarding the homogeneity of the thermal expansion, compressibility, length relaxations and also the long-term stability of samples.Length measurements with sub-nm uncertainties demand, besides the application of frequencystabilized lasers, the consideration of influences whose uncertainty contributions are difficult to minimize. For this purpose, various methods have been developed in the PTB in the last few years and these have been integrated into the measuring process. A new autocollimation process is cited as an example and this ensures that the lightwaves reach the surfaces of the measuring objects exactly perpendicularly. The so-called cosine error is hereby lowered to under 10–11 • L. Furthermore during the electronic evaluation of the interference pattern, the exact assignment of the sample position to the camera pixel coordinates is considered. This is particularly important when it comes to measuring objects whose end faces are non-parallel and when the influence of small temperature-induced changes of the lateral sample position can be corrected. By taking the temperature-related influence of the deflection of the end plate wrung to the back into consideration, the precision could be increased further. When taking thermal expansion measurements on typical samples, length measurement uncertainties of 0.25 nm are now achieved.
In a recently completed international comparison measurement, the leading position of the PTB in the determination of thermal expansion coefficients was confirmed. The new possibilities for the precise characterization of high tech materials are already being used intensively by companies working in the fields of optics and precision manufacturing.This text in the latest issue of PTB-news (08.2):
Erika Schow | alfa
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences