Spicer dual (2x) magnetic field cancelling system actively eliminates image interference in ferroelectric material research

The performance of an electron microscope operating at high levels of magnification can be affected by a whole host of external factors – such as vibrations and temperature variations – limiting the quality and resolution of the images generated. Magnetic field interference can be especially problematic, and equally challenging to rectify, often requiring the instrument to be placed in ‘quiet’ locations that do not best serve the lab workflow. Fortunately, dedicated magnetic field cancelling systems can be employed to actively eliminate external fields, allowing microscopes to perform to their specifications, producing high resolution images even in challenging locations. In this case study, Jinming Guo, Professor of Materials Science and Engineering at Hubei University in China, describes how a dual (2x) Spicer Consulting SC24 Magnetic Field Cancelling System is assisting in the study of ferroelectric materials at an atomic level.

Ferroelectric materials are dielectric substances that remain permanently polarised after the removal of an applied electric field; they are routinely used in applications ranging from energy conversion to data storage. The School of Materials Science and Engineering at Hubei University has an active ferroelectric research program, largely focused on understanding the relationship between the microstructures and macroscopic properties of these valuable substances. Prof. Guo explained: “We employ transmission electron microscopy (TEM) to study ferroelectric materials at the atomic scale, allowing us to gain valuable insights into the key mechanisms responsible for their unique characteristics. For example, we can use TEM to determine the polarisation vectors in perovskite unit cells. The relative displacement of ions that occur in these structures is in the order of tens of picometers, so such minute changes are only detectable at an instrument’s highest magnification and resolution settings.”

Unfortunately, the laboratory is just 70 meters away from a sandwich-structure road network containing a busy metro line (underneath), a high street and an overpass, which generates a large magnetic field with a strong gradient, causing intolerable levels of image distortion. Prof. Guo highlighted the scale of this problem: “To put this issue into perspective, our Thermo Scientific™ Spectra 300 TEM is rated to withstand external fields of up to 20 nanoTesla (nT), but the field generated by the subway is almost 4,000 nT – orders of magnitude higher than the acceptable limits. Such intense and non-uniform magnetic field interference was, therefore, severely compromising image quality, making our research activities extremely difficult. While passive shielding provided us with some protection against AC fields, we were still in need of a solution for our DC field problems.”

Hubei University considered solutions from several suppliers before choosing the SC24 Magnetic Field Cancelling System from Spicer Consulting. Prof. Guo explained the reasoning behind this decision: “We compared the SC24 to alternative systems, and concluded that its superior specifications made it the ideal solution to overcome the harsh environmental conditions present in our laboratory. Additionally, the expert advice and service from Ke Chieh Tech Ltd. – Spicer Consulting’s distributor in China – left us reassured that we were in safe hands.”

“After installing the Dual SC24 Magnetic Field Cancelling System on our Spectra 300 TEM, the external interference has been attenuated to well within the manufacturer specified range, and all values at X, Y, Z directions ranging from height of 3 meters to 0.5 meters are below 20 nanoTesla obtained by 4 detectors, allowing it to operate at its highest magnification and resolution levels with no issues from magnetic interference. The SC24 system is also incredibly easy to use, and it is remarkable to see the real-time difference in image quality when switching the unit on and off. Crucially, we know that comprehensive after-sales support is just a phone call away – backed by the joint expertise of Spicer Consulting and Ke Chieh Tech – so we would absolutely recommend the SC24 system to any other parties looking to purchase active magnetic field cancelling systems,” Prof. Guo concluded.

About Spicer Consulting Limited

Spicer Consulting magnetic field cancelling systems protect electron beam instruments, including SEMs, transmission electron microscopes, electron beam lithography tools and SEM-based metrology and inspection tools. They are located in some of the world's leading laboratories, universities, semiconductor manufacturing plants and test facilities of electron and ion beam equipment manufacturers. The company’s magnetic field, vibration and acoustic analysis systems have also been adopted as the standard for conducting site surveys by leading equipment manufacturers. Spicer Consulting is located in Stewartby, Bedfordshire, United Kingdom and prides itself on it's UK manufacturing heritage and commitment to excellence.

About Ke Chieh Tech Ltd. (K.C. Tech)

K.C. Tech is an advanced precision instrument and electron microscope imaging equipment supplier, using its experience and technical expertise to deliver professional nano imaging solutions to customers across Taiwan, China and the Asia-Pacific region. Website: https://kechieh.com.