Juyoung Jeong Yongwoo Lee Yoon Hee Jeong Jeehoon Kim Hye Jung Chang 2024-01-12T04:39:33Z 2024-01-12T04:39:33Z 2021-09-29 2019-11 - https://pubs.kist.re.kr/handle/201004/78347 Magnetic skyrmions with nontrivial topological spin configuration manifesting ultrahigh-efficiency manipulation current are of prime interest in modern magnetic device technology. Here we report an entirely new class of skyrmions in hard magnet using Lorentz TEM. In contrast to previously reported skyrmions, the new type of skyrmion and its variant appear only via field-cool procedure due to a high thermomagnetic irreversibility and show a high level of phase robustness. Futhermore, we also find and manipulate room-temperature skyrmionic bubble using in-situ heating and biasing TEM holder. The discovery and manipulation of skyrmions and skyrmionic bubbles in a rare earth material not only offers a new design principle for suited skyrmions via a control of the dual nature of f electrons, but also lifts a major hurdle for device applications arising from the narrow window of existing skyrmion materials. English 한국현미경학회 skyrmions Lorentz TEM hard magnet field cooling Magnetic skyrmion in hard magnet Conference 2 2019 한국현미경학회 학술대회 2019 한국현미경학회 학술대회 KO 경주 2019-11-14