-
Iron-based superconductor FeSexTe1–x has attracted attention because of its high upper critical field, low anisotropy, and high critical current density. Also, it is predicted to have nontrivial topological properties, so that it is a candidate of realizing Majorana fermion, when the superconductivity is combined with topological features. However, its flux pinning behavior and mechanism in superconducting state with varying Se/Te ratio have not been systematically studied . We use self-flux method to grow single crystal samples of FeSexTe1–x with different x values (0.3, 0.4, 0.5 and 0.6). The structural and morphological properties of the monocrystalline samples are characterized by XRD and SEM. All samples show that they possess the expected crystalline structures and their lattice parameters vary with x value. The magnetic properties at low temperatures are also measured, showing that all samples have good superconductivity. Superconducting properties, such as critical current densities and flux pinning force densities, are extracted from the magnetic measurements and analyzed, and the flux pinning behavior is discussed. The best Se:Te ratio is determined to be nearly 0.4/0.6 based on the comparison among these properties of different samples. By utilizing the Dew-Hughes theory and analyzing the pinning force density peak, the flux pinning mechanism in the best samples (x = 0.4, 0.5) can be regarded as the mixture of normal point pinning and Δκ
volume pinning. This work provides important information for the further study of the topological and superconducting properties of FeSexTe1–x. -
Keywords:
- FeSexTe1–x /
- topological superconductor /
- flux pinning /
- critical current density
[1] Kamihara Y, Hiramatsu H, Hirano M, Kawamura R, Yanagi H, Kamiya T, Hosono H 2006 J. Am. Chem. Soc. 128 10012
Google Scholar
[2] Kamihara Y, Watanabe T, Hirano M, Hosono H 2008 J. Am. Chem. Soc. 130 3296
Google Scholar
[3] Xu G X, Huang H, Zhang X P, Huang S Y, Ma Y M 2018 Acta. Phys. Sin-Ch. Ed. 20 67
[4] Wu Z F, Wang Z H, T ao J, Qiu L, Yang S G, Wen H H 2016 Supercond. Sci. Technol. 29 035006
Google Scholar
[5] Tapp J H, Tang Z, Lv B, et al. 2008 Phys. Rev. B 78 060505
Google Scholar
[6] Yuan F, Iida K, Grinenko V, Chekhonin P, Pukenas A, Skrotzki W, Sakoda M, Naio M, Sala A, Putti M, Yamashita A, Takano Y, Shi Z, Nielsch K, Hiihne R 2017 Aip. Adv. 7 065015
Google Scholar
[7] Bao W, Qiu Y, Huang Q, Green Q M, Zajdel P, Fitzsimmons M R, Zhernenkov M, Chang S, Fang M, Qian Q, Vehstedt E Q, Yang J, Pham H M, Spinu L, Mao Z Q 2009 Phys. Rev. Lett. 102 247001
Google Scholar
[8] Fiamozzi Zignani C, De Marzi G, Corato V, Mancini V, Vannozzi A, Rufoloni A, Leo1 V, Guarino A, Galluzzi A, Nigro A, Polichetti M, della Corte A, Pace S, Grimaldi G 2018 J. Mater. Sci. 132 84084
[9] Sun Y, Tsuchiyab Y, Yamadab T, Taenb T, Pyonb S, Shia Z X, Tamegai T 2014 Physica C 113 8656
[10] Abe H, Noji T, Kato M, Koike Y 2010 Physica C 980 8579
[11] Rößler S, Cherian D, Harikrishnan S, Bhat H L, Elizabeth S, Mydosh J A, Tjeng L H, Steglich F, Wirth S 2010 Phys. Rev. B 82 144523
Google Scholar
[12] Yadav C S, Paulose P L 2009 New J. Phys. 11 103046
Google Scholar
[13] Cieplaka M Z, Bezusyya V L 2015 Philos. Mag. 1478 6435
[14] Migita M, Takikawa Y, Takeda M, Uehara M, Kuramoto T, Takano Y, Kimishima Y 2011 Physica C 471 916
Google Scholar
[15] Wu Z F, Wang Z H, Tao J, Qiu L, Yang S G, Wen H H 2016 Supercond. Sci. Technol. 29 4
[16] Leo A, Guarino A, Grimaldi G, Nigro A, Pace S, Bellingeri E, Giannini E 2014 J. Phys.: Conf. Ser. 507 012029
Google Scholar
[17] Wu Z, Tao J, Xu X, Qiu L, Yang S, Wang Z 2016 Physica C 528 39
Google Scholar
[18] Zhuang J C, Yeoh W K, Cui X Y, Xu X, Du Y, Shi Z X, Ringer P S, Wang X I, Dou S X 2014 Sci. Rep.-Uk. 4 7273
[19] Gomez K W 2010 J. Nov. Magn. 23 551
Google Scholar
[20] Imai Y, Sawada Y, Nabeshima F, Maeda A 2015 Proc. Natl. Acad. Sci. 122 193
[21] Wang A F, Ying J J, Yan Y J, Liu R H, Luo X G, Li Z Y, Wang X F, Zhang M, Ye G J, Cheng P, Xiang Z J, Chen X H 2011 Phys. Rev. B 83 060512
Google Scholar
[22] Yeh K W, Huang T W, Huang Y I, Chen T K, Hsu F C, Wu P M, Lee Y C, Chu Y Y, Chen C L, Luo J Y, Yan D C, Wu M K 2008 Europhys. Lett. 84 37002
Google Scholar
[23] Bean C P 1994 Rev. Mod. Phys. 36 31
[24] Kumar R, Sudesh, Varma G D 2018 Aip. Adv. 8 055819
Google Scholar
[25] Bonura M, Giannini E, Viennois R, Senatore C 2012 Phys. Rev. B 85 134532
Google Scholar
[26] Shen B, Cheng P, Wang Z S, Fang L, Ren C, Shan L, Gu C Z, Wen H H 2010 Phys. Rev. B 81 014503
Google Scholar
[27] Galluzzi A, Buchkov K, Nazarova E, Tomov V, Grimaldi G, Leo A, Pace A, Polichetti M 2018 J. Appl. Phys. 123 233904
Google Scholar
-
图 1 (a) FeSexTe1–x 单晶样品X射线衍射图谱; (b) (001)随组分比例x的变化; (c)晶格参数c随x的变化
Figure 1. (a) X-ray diffraction pattern of FeSexTe1–x single crystal sample; (b) the (001) peak shifts with changing x; (c) lattice parameter c changes with Se content x.
图 2 FeSexTe1–x 样品的SEM图谱 (a) x = 0.3; (b) x = 0.4; (c) x = 0.5; (d) x = 0.6, 其中(b)图右上角为同一样品的另一个区域
Figure 2. SEM images of FeSexTe1–x samples: (a) x = 0.3; (b) x = 0.4; (c) x = 0.5; (d) x = 0.6. The upper right corner of Fig. (b) is another region of the same sample.
图 3 FeSexTe1–x (x = 0.3, 0.4, 0.5, 0.6)样品的磁化强度-温度(ZFC, FC)曲线
Figure 3. M-T (ZFC, FC) curves of FeSexTe1–x (x = 0.3, 0.4, 0.5, 0.6) samples.
图 4 FeSexTe1–x样品在磁场平行于样品c轴时不同温度下的磁滞回线 (a) x = 0.3; (b) x = 0.4; (c) x = 0.5; (d) x = 0.6
Figure 4. Hysteresis loops of FeSexTe1–x samples at different temperatures under the field parallel to c axis: (a) x = 0.3; (b) x = 0.4; (c) x = 0.5; (d) x = 0.6.
图 5 (a), (b)不同Se含量的FeSexTe1–x样品的Jc- H曲线 (a) T = 2 K, (b) T = 4 K; (c), (d) 不同Se含量的FeSexTe1-x样品归一化的钉扎力密度和约化磁场的关系 (c)T = 2 K, (d)T = 4 K
Figure 5. Jc- H curves of FeSexTe1–x samples with different Se contents: (a) T = 2 K, (b) T = 4 K; Fp/Fpmax - normalized field curves: (c) T = 2 K, (d) T = 4 K.
表 1 Fp-h曲线的Dew-Hughes公式拟合参数值
Table 1. Fitted parameters of Fp curves.
T = 2 K T = 4 K p q Fp峰位 p q Fp峰位 x = 0.4 1.647 2.461 0.4013 1.996 2.233 0.4654 x = 0.5 1.632 2.870 0.3552 2.001 2.335 0.4398 
DownLoad: CSV
-
[1] Kamihara Y, Hiramatsu H, Hirano M, Kawamura R, Yanagi H, Kamiya T, Hosono H 2006 J. Am. Chem. Soc. 128 10012
Google Scholar
[2] Kamihara Y, Watanabe T, Hirano M, Hosono H 2008 J. Am. Chem. Soc. 130 3296
Google Scholar
[3] Xu G X, Huang H, Zhang X P, Huang S Y, Ma Y M 2018 Acta. Phys. Sin-Ch. Ed. 20 67
[4] Wu Z F, Wang Z H, T ao J, Qiu L, Yang S G, Wen H H 2016 Supercond. Sci. Technol. 29 035006
Google Scholar
[5] Tapp J H, Tang Z, Lv B, et al. 2008 Phys. Rev. B 78 060505
Google Scholar
[6] Yuan F, Iida K, Grinenko V, Chekhonin P, Pukenas A, Skrotzki W, Sakoda M, Naio M, Sala A, Putti M, Yamashita A, Takano Y, Shi Z, Nielsch K, Hiihne R 2017 Aip. Adv. 7 065015
Google Scholar
[7] Bao W, Qiu Y, Huang Q, Green Q M, Zajdel P, Fitzsimmons M R, Zhernenkov M, Chang S, Fang M, Qian Q, Vehstedt E Q, Yang J, Pham H M, Spinu L, Mao Z Q 2009 Phys. Rev. Lett. 102 247001
Google Scholar
[8] Fiamozzi Zignani C, De Marzi G, Corato V, Mancini V, Vannozzi A, Rufoloni A, Leo1 V, Guarino A, Galluzzi A, Nigro A, Polichetti M, della Corte A, Pace S, Grimaldi G 2018 J. Mater. Sci. 132 84084
[9] Sun Y, Tsuchiyab Y, Yamadab T, Taenb T, Pyonb S, Shia Z X, Tamegai T 2014 Physica C 113 8656
[10] Abe H, Noji T, Kato M, Koike Y 2010 Physica C 980 8579
[11] Rößler S, Cherian D, Harikrishnan S, Bhat H L, Elizabeth S, Mydosh J A, Tjeng L H, Steglich F, Wirth S 2010 Phys. Rev. B 82 144523
Google Scholar
[12] Yadav C S, Paulose P L 2009 New J. Phys. 11 103046
Google Scholar
[13] Cieplaka M Z, Bezusyya V L 2015 Philos. Mag. 1478 6435
[14] Migita M, Takikawa Y, Takeda M, Uehara M, Kuramoto T, Takano Y, Kimishima Y 2011 Physica C 471 916
Google Scholar
[15] Wu Z F, Wang Z H, Tao J, Qiu L, Yang S G, Wen H H 2016 Supercond. Sci. Technol. 29 4
[16] Leo A, Guarino A, Grimaldi G, Nigro A, Pace S, Bellingeri E, Giannini E 2014 J. Phys.: Conf. Ser. 507 012029
Google Scholar
[17] Wu Z, Tao J, Xu X, Qiu L, Yang S, Wang Z 2016 Physica C 528 39
Google Scholar
[18] Zhuang J C, Yeoh W K, Cui X Y, Xu X, Du Y, Shi Z X, Ringer P S, Wang X I, Dou S X 2014 Sci. Rep.-Uk. 4 7273
[19] Gomez K W 2010 J. Nov. Magn. 23 551
Google Scholar
[20] Imai Y, Sawada Y, Nabeshima F, Maeda A 2015 Proc. Natl. Acad. Sci. 122 193
[21] Wang A F, Ying J J, Yan Y J, Liu R H, Luo X G, Li Z Y, Wang X F, Zhang M, Ye G J, Cheng P, Xiang Z J, Chen X H 2011 Phys. Rev. B 83 060512
Google Scholar
[22] Yeh K W, Huang T W, Huang Y I, Chen T K, Hsu F C, Wu P M, Lee Y C, Chu Y Y, Chen C L, Luo J Y, Yan D C, Wu M K 2008 Europhys. Lett. 84 37002
Google Scholar
[23] Bean C P 1994 Rev. Mod. Phys. 36 31
[24] Kumar R, Sudesh, Varma G D 2018 Aip. Adv. 8 055819
Google Scholar
[25] Bonura M, Giannini E, Viennois R, Senatore C 2012 Phys. Rev. B 85 134532
Google Scholar
[26] Shen B, Cheng P, Wang Z S, Fang L, Ren C, Shan L, Gu C Z, Wen H H 2010 Phys. Rev. B 81 014503
Google Scholar
[27] Galluzzi A, Buchkov K, Nazarova E, Tomov V, Grimaldi G, Leo A, Pace A, Polichetti M 2018 J. Appl. Phys. 123 233904
Google Scholar
DownLoad:
Catalog
Metrics
- Abstract views: 8222
- PDF Downloads: 220
- Cited By: 0
