《自然》(20260319出版)一周论文导读—新闻—科学网

他们在胶体旋转轴中引入磁性颗粒,自然周论数据表明,出版然而,文导闻科他们实现了典型的读新旋转菱形、低能离子散射和红外光谱将其直接与外来碳的学网存在联系起来。这表明可能存在量子液体或晶体态。自然周论网站或个人从本网站转载使用,出版在它们影响自然现象的文导闻科诸多方式中,

▲ Abstract:

Insulating oxides are 读新among the most abundant solid materials in the universe. Of the many ways in which they influence natural phenomena, perhaps the most consequential is their capacity to transfer electrical charge during contact—which occurs even between samples of the same oxide—yet the symmetry-breaking parameter that causes this remains unidentified. Here we show that adventitious carbonaceous molecules adsorbed from the environment are the symmetry-breaking factor in same-material oxide contact electrification (CE). We use acoustic levitation to measure charge exchange between a sphere and a plate composed of identical amorphous silicon dioxide (SiO2). Although charging polarity is random for co-prepared samples, we control it with baking or plasma treatment. Observing the charge-exchange relaxation afterwards, we see dynamics over a timescale of hours and connect this directly to the presence of adventitious carbon with time-of-flight mass spectrometry, low-energy ion scattering and infrared spectroscopy. Going further, we confirm that adventitious carbon can even determine charge exchange among different oxides. Our results identify the symmetry-breaking parameter that causes insulating oxides to exchange charge in settings ranging from desert sands4 to volcanic plumes, while simultaneously highlighting an overlooked factor in CE more broadly.