Xu Lin-Xi, Zhu Rong-Qi, Zhu Zhu-Qing, Gong Li-Ping, Gu Bing. High-purity longitudinal needle-shaped magnetization fields produced in uniaxial crystalsJ. Acta Physica Sinica, 2022, 71(14): 147801. DOI: 10.7498/aps.71.20220316