How best can India, and the world, deal with China’s chokehold on magnets?

by Hansraj Agrawal | Jun 15, 2025 | Science

STRONG PULL: China holds nine-tenth of the world’s reserves of neodymium, key to making rare earth magnets
| Photo Credit:
Nelson Ching

When Masato Sagawa revolutionised industry by inventing a strange concoction of elements — neodymium, iron and boron — that could be powdered and sintered into an alloy of exceptional magnetic properties, little could he have foreseen that he was putting the world in the stranglehold of China.

By a quirk of fate, China not only has about nine-tenths of the neodymium discovered on planet earth, but also large swathes of sparsely inhabited land in the Inner Mongolia region, where it refines neodymium without facing as much as a murmur of protest over the environmentally hazardous process.

And today, China is flexing its biceps by placing export restrictions on neodymium. Magnets are at the core of everything from motors to transformers; China holds the cards.

“It is a global problem,” says Dr D Prabhu, scientist at Hyderabad-based International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), who has worked extensively on magnets.

Sobering challenges

On the quest for alternatives to magnets from China, Prabhu drove home a sobering reality. “All the leading scientists of the world,” he said, “are of the view that for at least the next two decades, there is nothing that comes even close to neodymium-iron-boron (NIB) magnets.”

The expert reeled out some discouraging numbers. NIB has ‘maximum energy product’ — a measure of the magnetic energy a material can store — of 35-52 MGOe (mega gauss oersted); the next best is samarium-cobalt, with 17-26 MGOe.

The common ferrite magnets have 3-5 MGOe. (The more familiar ‘tesla’ unit of magnetism measures the strength of a magnetic field at a given point.)

What about samarium-iron-nitride (SmFeN)? There are tomes of scientific literature extolling SmFeN’s virtues, with some even talking of it as a replacement for NIB. Mouthwateringly, samarium is available in sufficient quantities in India.

Sorry, says Prabhu. Indeed, SmFeN has MGOe numbers that can rival NIB’s, but it is impossible to produce through the conventional sintering process — the material decomposes at high temperature. Yes, one can make ‘bonded magnets’ with SmFeN, using materials like resin, but their MGOe numbers are much lower.

Despite these disheartening scenarios, India (and the world) may still have ways to counter China’s dominance over powerful magnets.

Way forward

Here’s what lies within the realm of possibility.

One, finding more neodymium is the world’s best hope. Australia has begun digging for it. With large uninhabited areas, it can possibly do its own refining, too. But that is just hope — and a long-term option.

Two, finding a way to make SmFeN magnets with high MGOe. Technologists are working furiously on this. In a paper published in Materialia, a group of American scientists (including three of Indian origin) say they have developed an SmFeN magnet with MGOe of 23.4, using metals such as aluminium, copper, iron and zinc as binders, instead of resin. The magnet, they add, displays high coercivity, which measures its resistance to de-magnetisation.

This option, too, is still in the labs; it must cross the ‘valley of death’ to the industry. Not an option for Monday morning.

Yet, the industry can switch to SmFeN bonded magnets wherever possible. SmFeN magnets with MGOe of around 25 are hitting the market.

A February 2025 market research found that these magnets are good for applications in certain areas of electric vehicles, robotics, consumer electronics and wind turbines. That said, it should be noted that SmFeN manufacturing technologies are heavily patented, and India needs to develop its own process. Some experts have called for a ‘national mission on magnets’.

Three, reducing the quantity of neodymium needed per magnet, by inventing processes that slash wastage — such as ‘near net-shaped’ magnets. While permanent magnets are typically made by magnetising blocks of material and then cutting and machining them to the desired size, near net-shaped magnets are made directly to the desired shape, cutting wastage of material.

In fact, such a process has been developed and patented by Sagawa, who has licensed it to ARCI. The ARCI is putting up a first-of-its-kind pilot project in Hyderabad. A team of ARCI scientists, including Prabhu, are in Japan for training. The project could start next month, and the first magnet is likely to roll out in six months.

Four, developing products such as EV motors that can work with indigenous magnets.

One example is a motor developed by Chennai startup Viridian Ingini Propulsion. The ‘permanent magnet-assisted synchronous reluctance motor’, a kind of hybrid motor, uses ferrite magnets that can be easily made in India. Viridian is readying to produce these motors for electric two- and three-wheelers.

Sagawa, 81, is still active. It is not known if he rues the fact that his singular invention has unwittingly added geopolitical muscle to China, but the octogenarian may still have some tricks up his sleeve. He is said to be favourably disposed towards India. One lives on hope.

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Published on June 15, 2025

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Creep-resistant aircraft part

by Hansraj Agrawal | Jun 15, 2025 | Science

In aircraft engines, nickel-based superalloys are extremely important — they make up about half the weight of the engine because they can withstand very high temperatures and stress. One such alloy is Inconel 718 (IN718), valued especially for its creep resistance — that is, ability to resist deforming when exposed to high heat for long periods. This makes it ideal for jet and rocket engine parts.

However, when IN718 is made using additive manufacturing (AM) — a 3D printing-like process — its creep resistance is worse than when made the traditional way (called ‘wrought’ processing).

The reason for that wasn’t clearly understood — until now.

Researchers at IIT-Madras have discovered both the cause and the solution.

They found that in AM-processed IN718, a metal called niobium doesn’t spread evenly. Instead, it gathers at the grain boundaries — the microscopic zones between crystal-like regions in the metal. This unevenness creates soft spots next to the grain boundaries, known as precipitate-free zones (PFZs), which are weak and reduce the metal’s ability to withstand creep.

In traditional methods, these problems are fixed later, during the forging and heating steps, which helps niobium spread evenly. But in AM, where parts are printed directly to shape, this step is skipped, and the segregation problem remains.

To fix this, the researchers tried heating the AM metal to a higher temperature (1,150 degrees C) than usual, giving niobium atoms more energy to move and spread out. They carefully balanced this to avoid damaging the metal’s structure. “The long-term exposure heat treatment methodology demonstrates that PFZs are the major influencing factor responsible for microsegregation-dependent creep rupture behaviour,” the scientists say in a paper.

The new treatment successfully removed the soft PFZs and made the material much more creep-resistant — improving its performance by five times compared to the standard heat treatment.

This breakthrough could make 3D-printed IN718 parts practical for real-world use in aircraft and space engines.

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Published on June 15, 2025

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Ultrasonic whispers

by Hansraj Agrawal | Jun 1, 2025 | Science

A group of Chinese-American scientists at the University of Pennsylvania has figured out a way to deliver audio (music, podcasts and so on) right into your ear, without you having to wear earbuds or headphones, even as those around you cannot hear any of it.

The challenge of delivering audible content to a targeted listener has flummoxed sound engineers but a breakthrough, which still requires some fine-tuning, has been achieved.

Suppose you want to listen to a podcast. The audio file is stored in the car’s stereo system. The stereo system converts the podcast’s regular audio waves into ultrasonic signals — these signals are inaudible because they’re too high-pitched for human ears. However, the ultrasonic waves are so carefully aimed that they cross each other right where your head is — and they become audible sounds.

As long as your head — and ear — is in the ‘audio bubble’, you will hear the podcast. If you move your head, you will hear nothing.

The sound quality isn’t perfect yet. The scientists are working with machine learning techniques to improve the technology, according to a PNAS paper. Yun Jing, who led the research, believes that the technology has some interesting applications, ranging from home theatres to device-free communications.

Some caution that ultrasounds may harm your ear — but that’s another matter.

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Published on June 1, 2025

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Can hospital visits help predict the risk of suicide?

by Hansraj Agrawal | Jun 1, 2025 | Science

TIMELY AID: Healthcare settings play a critical role in suicide prevention
| Photo Credit:
Abdullah Durmaz

Death by suicide is not only a tragic loss of life but also leaves a searing impact on families.

A paper published late last year in the NPJ Mental Health journal showed that probability and machine-learning models built using logistic regression and random forest concepts can predict suicide risk better than existing methods.

A logistic regression estimates the probability of an event occurring, while a random forest model is a machine-learning algorithm that uses an ensemble of ‘decision trees’ to make predictions.

Researcher Roy Adams and others used electronic health record data in the US to test these models, which were able to predict suicide risk 83 per cent of the time, as compared with 64 per cent in the case of the screening methods currently used in the West. A 50 per cent success is as good as leaving things to chance.

The authors emphasise that healthcare settings play a critical role in suicide prevention, noting that about 72 per cent of suicide attempts and 50 per cent of suicide deaths happened within 90 days of contact with the health system. This, they say, highlights the scope for intervention within these settings.

Age factor

The study analysed health record data from over 3,31,000 visits by more than 16,000 adults to American-Indian health service providers between 2017 and 2021. In this period, there were 417 suicide attempts and 37 deaths by suicide.

The study found that suicide attempt or death was associated with younger age, a diagnosis of depression, anxiety, bipolar disorder, post-traumatic stress disorder or suicidal ideation, a diagnosis related to alcohol, cannabis or other substance abuse, and a past positive screen for intimate partner violence, suicide risk or depression.

Though the study was intended to help reduce suicide risk among American-Indian and Alaska Native populations, the approach could well apply to India, which has the highest number of suicides in the world and needs timely and targeted interventions to help save lives.

Deaths by suicide increased from 9.9 per one lakh population in India to 10.4 between 2017 and 2019, and then further to 12.4 by 2022, according to the National Crime Records Bureau data. The latest data show that nearly 34 per cent of suicides was in the 15-30 age group.

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Published on June 1, 2025

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Future of data centres: It’s all in the DNA

by Hansraj Agrawal | Jun 1, 2025 | Science

Imagine a large data centre of this kind: it has no semiconductor chips, it consumes no energy, its land footprint is small, and yet it stores far more information than any of today’s hyperscale data centres. Instead of semiconductors, it has hundreds of vials holding a liquid — an aqueous solution of DNA molecules.

Sounds far-fetched, like science fiction? Think again. Later this month, an interesting conference is to be held at the Sarbonne University, Paris, titled ‘Storage and computing with DNA, 2025’. If you break it down to its components — DNA storage and DNA computing — you are looking at a fascinating future of information technology, one built without semiconductors and with only factory-made DNA.

Storing data — and, by extension, computing — in the form of DNA is not a new idea. As a concept, it has been around for over half a century and, as a technology, for a dozen years. As a group of Chinese scientists note in a paper published in Synthetic and Systems Biology, the idea of using DNA for data storage was outlined independently by two scientists — Norbert Wiener of the US and Mikhail Neiman (erstwhile USSR) — almost at the same time at the release of IBM’s first hard disk in the 1960s.

Evolving technology

In 2012, a team led by George Church, a professor of genetics at Harvard Medical School and a founding core faculty member of the Wyss Institute, successfully encoded his book Regenesis: How synthetic biology will reinvent nature and ourselves into DNA. This project demonstrated the potential of DNA as a high-density, long-term data storage medium. In 2020, at the University of Texas at Austin, a research team that included scientist Stephen Jones and molecular biologist Ilya Finkelstein encoded the novel The Wonderful Wizard of Oz into DNA. They developed an advanced error-correction method for accurate retrieval of data even under harsh conditions.

Information storage is all about coding. In the past, messages transmitted using Morse code involved the use of dots and dashes to represent the letters of the alphabet — so, for instance, you have three dots for ‘s’; three dashes for ‘o’; and a combination of three dots, three dashes, and three dots for ‘SOS’.

In the computing era, coding involves combinations of zeroes and ones.

Coding using DNA molecules relies on their twisted ladder structure, where sugars and phosphate molecules form the rails, and pairs of nucleotides — adenine (A), thymine (T), cytosine (C) and guanine (G) — form the rungs. The nucleotides can stand in for the dots and dashes in Morse code, since A will only pair with T, and C only with G. Information can be stored as combinations of A-Ts and C-Gs. Since DNA can be synthesised, you can make any DNA of your choice to store data.

As such, DNA storage is not futuristic, but an evolving technology. The problem essentially has to do with the cost of synthesising DNA — $3,500 for 1 megabyte of information, according to one estimate. However, the cost is coming down, as is the ease of synthesising DNA. People are even talking of bench-top DNA synthesisers, the size of a mini fridge.

So, are we looking at an era of ‘DNA data centres’?

Karthik Raman, Professor of Data Science and AI, Department of Biotechnology, IIT-Madras, says it is “definitely possible” although a lot more work is needed.

The proof-of-concept has been established, he says.

Microsoft, which plans to spend $80 billion to build data centres in 2025, has been working on DNA data centres for some years. “Using DNA to archive data is an attractive possibility because it is extremely dense — up to about 1 exabyte per cubic millimetre,” Microsoft said a decade ago. “While this is not practical yet due to the current state of DNA synthesis and sequencing, these technologies are improving quite rapidly with advances in the biotech industry.”

Perhaps the “not practical yet” factor still holds. While DNA synthesising is getting cheaper (sequencing is already very cheap), there are other concerns, such as lack of accuracy — there is a one per cent chance that a nucleotide combination may not represent the data correctly. And one must also factor in the energy involved in synthesising DNA, though it is likely to be far less than what current data centres consume.

DNA computing

If DNA storage is here, can ‘DNA computing’ be far behind? However, the concept of a liquid computer powered by DNA is still an emerging one. A recent article speculates on the development of a DNA-powered supercomputer capable of (say) 100 billion tasks at once.

DNA storage and computing is the ‘watch this space’ area of technology, whose implications are unimaginable.

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Published on June 1, 2025

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Efficient effluent treatment through photocatalysis

by Hansraj Agrawal | Jun 1, 2025 | Science

The release of industrial chemical waste into waterbodies is a global concern; the approach to tackling this has generally involved the use of catalytic materials that rely on sunlight to drive chemical reactions. However, most photocatalysts are difficult to reuse, limiting their practicality in largescale applications. Further, these catalysts require ultraviolet (UV) light to drive the conversions, which necessitates dedicated UV sources, adding to the complexity and cost of the system.

A team of researchers at NIT-Rourkela, led by Prof Subhankar Paul of the Biotechnology and Medical Engineering department, has developed an innovative photocatalyst system.

The system combines iron-doped nano-titania with graphene oxide and immobilises the compound on specially designed spherical concrete beads.

These beads are made from green concrete using coal fly ash derived zeolite, a sustainable approach that repurposes industrial waste and offers high mechanical strength, porosity and absorption capacity. This composite material uses sunlight to break down toxic pollutants in wastewater efficiently.

The photocatalyst beads can be added to the wastewater reservoir, exposed to sunlight and easily removed once the water treatment is complete.

Since the developed technology does not rely on external energy sources, it can be used easily in rural and resource- constrained areas.

This technology has the potential to treat industrial effluents, municipal wastewater and contaminated natural water sources.

“As the global concerns over water pollution continue to grow, this NIT- Rourkela innovation provides a timely and sustainable response to address the challenge,” says a press release from the institute.

Eco-safe lubrication

Lubrication reduces friction and wear in machinery, ensuring efficiency and longevity. Conventional mineral or synthetic oil-based lubricants pose environmental risks, driving the demand for sustainable alternatives. Scientists at the Institute of Advanced Study in Science and Technology (IASST), Guwahati, have developed an environmentally friendly lubricant formulation that significantly enhances friction reduction, wear resistance and overall performance. The lubricant has been developed by integrating surface-modified graphitic carbon nitride into bio-based castor oil.

This advancement offers a sustainable alternative to conventional lubricants, addressing both efficiency and environmental concerns.

A study of friction, lubrication and wear of interacting surfaces in relative motion (tribological evaluations) demonstrated remarkable improvements — reduction of friction by around 54 per cent and decrease of wear volume by 60.02 per cent compared to castor oil alone. The lubricant also exhibited a higher load-bearing capacity and greater thermal stability, with the oxidation onset temperature rising from 320 degree C to 339 degree C, demonstrating the efficiency of the lubricating formulation. Further, toxicity assessments confirm minimal formation of free radicals (thereby curbing secondary reactions), making the formulation safe for environmentally sensitive applications.

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Published on June 1, 2025

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