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Feng Wang, Wei Fu and Jijie Huang3,∗ 1 Department of Vehicle Engineering, Changzhou Vocational Institute of Mechatronic Technology, Changzhou, Jiangsu 213164, People’s Republic of China 2 Qingdao Special Service Sanatorium of PLA Navy, Qingdao, Shandong 266000, People’s Republic of China 3 School of Materials, Sun Yat-sen University, Guangzhou, Guangdong 510275, People’s Republic of China E-mail: [email protected] This is a viewpoint on the letter by Yue Wu et al (2021 Supercond. Sci. Technol. 34 05LT01). The high-temperature superconductor (HTS) with critical temperature (Tc) over liquid nitrogen temperature was discovered by Wu et al [1], which is a milestone for the practical application of HTS. Actually, the bismuth strontium calcium copper oxide (BSCCO) (such as Bi-2212 and Bi-2223) is the first generation (1G) coated conductor since late twentieth century [2]. Many companies have the capability of produce kilometer long tape, such as American Superconductor Corporation (USA), Sumitomo Electric Industries, Ltd (Japan), Bruker (Germany), etc. The second (2G) generation coated conductor is based on rare-earth barium copper oxide (REBCO), which has advantages of more cost-effective, low ac loss and better in-field performance at higher temperature compared to 1G coated conductors. Therefore, 2G coated conductors are more promising for various applications such as motors, generators, transformers and transmission cables [3, 4]. One of the biggest challenges is how to fabricate 2G coated conductors or superconducting tapes with longer length and high in-field performance. Rolling-assisted biaxially textured substrates (RABiTS) and ion-beam-assisted deposition (IBAD) are the two major methods to fabricate the flexible metal tapes [5, 6]. Then, different approaches have been developed to deposit superconducting thin films on those metal tapes, including metal organic deposition using trifluoroacetates (TFA-MOD) [7], metalorganic chemical vapor deposition [8], and pulsed laser deposition (PLD) [9]. All of these methods have been employed for long coated conductor tapes processing, however, their superconducting properties need further improvement, especially in-field performance at high temperature. Artificial pinning centers (APCs) can lead to significantly enhanced in-field current carrying capacity (critical current density Jc), by acting as pinning centers to pin the magnetic vortices. Various APCs have been designed with different geometries, such as 0D nanoparticles [10], 1D nanocolumns [11] and 2D nanolayers [12]. 1D APCs refer to the nanocolumns embedding in REBCO matrix vertically aligned along c-axis, which results in enhanced Jc values especially when applied magnetic field B is parallel to the nanocolumns. Some typical dopants can form 1D nanocolumns in REBCO, including BaSnO3 (BSO) [13], BaZrO3 (BZO) [14], BaHfO3 (BHO) [15], YBa2(Nb/Ta)O6 [16], etc. The shape of the dopants is highly dependent on the growth conditions, for example, BSO,