source:New Straits Times
In 2013, scientists were able to develop an atomic clock that set a record for stability. In fact, if this clock had been started at the beginning of the universe's existence, some 14 billion years ago, it would be off today by less than a second.
This can be accomplished by using a rare earth element (REE) called ytterbium. Earlier atomic clocks used different elements and response to electromagnetic waves. However, ytterbium optical-based clock responds to a higher frequency laser, hence a more stable and better precision.
Atomic clocks have been around for decades and are essential for maintaining timekeeping standards, such as the clocks on GPS satellites. It is the time-keeping element that keeps our lives running smoothly, from phones and computer networks to financial markets and automated teller machines.
The International System of Units (SI units) defines a second as the time it takes for a caesium-133 atom to oscillate exactly 9,192,631,770 times.
A new discovery made in 2018 on the ytterbium atomic clock has opened up many exciting implications for scientific research, such as sensing weak signals from the earth's gravitational waves, shape and even dark matter, proving that REEs are most definitely a keystone to today's technology.
Without lanthanides, space exploration would probably be 50 years behind where it is today, and we'd still be using the land line to call home, GrabFood may not exist and research would take place in libraries of brick and mortar. Lanthanides have become so central to technology that world powers recognise its value and importance.
The lanthanides consist of elements with atomic number 57 (lanthanum) to 71 (lutetium). In the periodic table, they are arranged in a row in what is known as the f-block. This is so named because the electron configuration of these elements is defined by the filling of the f-orbital electron subshell.
What electrons need is space. More space provides the electrons flexibility, hence versatility. It is intriguing that atoms of REE may contain unpaired electrons due to incomplete filling of the f-orbital, which may contain at the most up to 7 unpaired electrons, following the Hund's Rule.
The fascinating part is that the high occupation of the unpaired electrons of its f-orbital leading to high saturation magnetisation had resulted in tremendous clean and green technology-driven economy. Screening of the f-
orbitals is captivating as the REEs do not only exhibit similar magnetic properties, but also physical, optical and chemical properties.
Some knowledge will help contextualise the crucial role played by REEs in Industry Revolution 4.0. Consider the neodymium magnet, the most powerful permanent magnet available today.
It is made of an alloy of neodymium (a lanthanide with atomic number 60), iron and boron, and its applications are too numerous to mention — used in computer hard drives, loudspeakers and especially electric motors and generators.
The latter two are particularly important for sustainable technologies as they are used in wind turbines and the electric drive system of hybrid and electric vehicles. Hybrid vehicles' battery needs REEs, too!
And the smartphone. Aside from the battery and speaker, the colours of its screen are made possible with yttrium, europium, and terbium. Medical equipment, like MRI machines, need REEs, also to make lasers for scientific and industrial purposes while the 5G network is dependent on fibres doped with erbium, another REE.
The importance of REEs to all sorts of industries cannot be overstated. Think about green technologies. The United States is aiming to have 20 per cent of its energy wind-generated by 2030 (from seven per cent today), while the United Kingdom is even more ambitious, wanting to have all its homes powered by wind by 2030.
Sourcing the REEs for projects such as these will be a key focus for these world powers going forward — and may result in some interesting political situations. China is the world's most dominant supplier of rare earth elements with 132,000 tonnes produced in 2019, followed by US with 26,000 tonnes.
This is where Malaysia can come in. As mentioned in the previous article, the US Geological Survey estimates some 30,000 metric tonnes of rare earth ores in Peninsular Malaysia.
It gives us the rare opportunity to make decisive steps to master the knowledge surrounding REEs — of their applications, and their exploration, mining and refinement.
In Part 3: The education game plan for rare earth elements: Where do we start? How will it work? Are we able to get on the right track?
The writer is a physicist specialising in electromagnetics, nanotechnology, and Lanthanide and Ferrite-based magnetic materials. She is a board member of Perak Eclat Technical and Vocational Education and Training (TVET), an organisation set up to assist the Perak state government in implementing TVET initiatives to help train manpower for the state's many industries