The realm of physics might be on the brink of a major shift. At least, that’s the sentiment being echoed by some social media aficionados—but there’s potential truth in it, especially if the recent findings from a Korean research team hold up under further scrutiny. In a time when power equates to value, such a revelation could resonate on a global scale. The elements in focus? Lead and copper. A superconductor that operates at room temperature is the ultimate objective in the electronics world. Such a conductor would let circuits function devoid of any electrical impedance, implying our gadgets would consume less power than they currently do. The superconductors familiar to us today demand significant chilling using agents like liquid helium, and in more modern contexts, liquid nitrogen—making the adoption of superconductors a pricey affair.
Scientists Sukbae Lee, Ji-Hoon Kim, and Young-Wan Kwon from Korea University garnered attention with their “not-so-well-organized” preliminary report suggesting a novel substance, dubbed “LK-99”, showcases superconductivity under normal atmospheric pressure and at temperatures exceeding those of a standard room. The announcement met with skepticism, but the scientific community has been eager to replicate their findings. The feedback remains divided on the legitimacy of these claims, with some positing that LK-99 might merely possess magnetic characteristics. The prevailing sentiment, however, indicates that the discovery isn’t a fabricated ruse (as has been the case with past such assertions), hinting that, regardless of the final verdict, LK-99 introduces us to a captivating new category of substances.
Superconductivity is an uncommon occurrence where electrical current flows through a substance without encountering any resistance. In other words, electrons traverse a superconductor without any interactions with the atoms inside. Considering how tightly atoms are positioned in solid materials, it’s no wonder this is an infrequent event, occurring only under distinct conditions. The potential benefits of superconductivity encompass absolute efficiency in equipment, translating to significant energy conservation. Present estimations suggest that approximately 6% of energy from power facilities dissipates as heat before reaching our residences. In specialized sectors, a room temperature superconductor could significantly reduce the operational expenses of MRI devices and pave the way for physicists working on the so-called cold fusion.
The pioneer superconductor, solid mercury, was unveiled in 1911 by the Dutch scientist Heike Kamerlingh Onnes, leading him to receive the Nobel accolade in 1913. While mercury is typically in liquid form at ambient temperatures, it becomes solid at around -38°C and only demonstrates superconducting qualities when chilled by liquid helium. Helium remains in a liquid state at temperatures beneath 4.2 Kelvin, very near to the absolute zero mark (0 Kelvin) and comparable to the chilling void of cosmic space. Understandably, the scientific community has since been on a quest to identify superconductors that function at elevated temperatures. Given helium’s scarcity and the high expenses linked to its cooling, the energy conservation from superconductivity often gets overshadowed by its associated cooling expenditures. This raises the question: why is there still interest in using them?
Due to their capacity to transport amplified currents compared to conventional wires, superconductors are excellent choices for electromagnets. They can produce significantly potent magnetic fields than other methods, proving indispensable in devices like MRI scanners and particle accelerators, such as the LHC located in Switzerland. This trait is somewhat paradoxical, especially when you consider the prominent feature of superconductivity, the Meissner effect. Despite their aptitude in generating them, superconductors aren’t compatible with intense magnetic fields. Credited to Walther Meissner for his revelation in 1933, the Meissner effect refers to the complete ejection of magnetic fields from the substance.
This occurs solely beneath what experts term the pivotal temperature: the temperature beneath which the substance exhibits superconductivity. It’s brought about by powerful electrical flows gliding atop the substance; the superconductor transforms into a potent magnet to repel external magnetic influences. This is the reason superconductors hover over magnets, a frequently highlighted clear illustration of the change. Yet, in addition to its temperature restrictions, a superconductor can endure only a certain magnitude of magnetic field before it “succumbs” and reverts back to a relatively regular substance. Like many marvels in science, superconductivity is often accompanied by conditions that render it beneficial only under particular situations.
The latter half of the 20th century witnessed substantial advancements in superconductivity concepts, paired with the unearthing of substances with progressively higher pivotal temperatures. The unveiling of superconductors with pivotal temperatures surpassing 77 Kelvin (the evaporating temperature of liquid nitrogen) merited IBM scientists Bednorz and Müller the Nobel Prize in 1987. Historically, superconductors have been categorized as either “Type 1” or “Type 2”, with Type 2 typically showcasing higher pivotal temperatures and functioning based on a distinct method. As of this moment (excluding the recent assertion), the warmest superconductor identified has a pivotal temperature of -23°C. This compound, lanthanum decahydride, is coolable with dry ice. Achieving superconductivity at this warmth necessitates subjecting the substance to profound pressure: 170 Giga Pascals, a pressure comparable to that of Earth’s inner core.
Given the aforementioned details, the assertion of a substance that exhibits superconductivity at standard pressure and room temperatures outpaces all prior studies in this domain. This is the driving force behind materials experts scrambling to reproduce this discovery in their facilities (and it’s also the reason many are still apprehensive). Some, however, are optimistic. Analysis conducted by Sinéad Griffin at Berkeley, University of California, suggests the feasibility of such superconductivity at these conditions, providing a tentative theory behind its occurrence. Research facilities in the USA communicated through Twitter their success in causing the material to float over a magnet. On August 2nd, Southeast University in China reported zero resistance at 110 kelvin (nearing the prevailing record for regular pressure) and a distinct resistance pattern. Some institutes have confirmed the production of this substance without observing any remarkable behaviors. Another study deduced that the likelihood of diamagnetism (another levitating characteristic) manifesting in the material without accompanying superconductivity is slim. LK-99 was conceived in 1999 by Korean scientists Sukbae Lee and Ji-Hoon Kim; teams have been delving into its attributes for years. The publication of a draft on the preprint platform ArXiv, following two unsuccessful patent applications, ignited the current surge of interest.
The realm of ambient temperature superconductivity has encountered deceit and incorrect findings, mirroring the ancient investigations into alchemy. It’s within this historical context that materials researchers operate; any proclamation of this sort is audacious and thus attracts deep scrutiny. Authorities are split on whether this early release and subsequent flurry benefits the science world. Publications like Nature function on a peer-assessment model—meaning, for an article to see the light of day, typically other entities have attempted to duplicate the study and confirmed it. Still, this hasn’t prevented deceitful reports from evading notice. The excitement related to LK-99 has instigated a surge of fresh articles in a brief span, and accompanying this, a considerable amount of web-based false information. It’s still uncertain if LK-99 stands as a milestone not only in materials study, but also in the methodology of scientific research. In general, outcomes are largely variable, and theory experts argue that producing LK-99 is challenging and capricious. Given the intricate nature of the procedure and the possible novel physics at play, it might be a while before researchers discern the reality of LK-99.