Strength of effective Coulomb interaction in two-dimensional transition-metal halides MX2 and MX3 (M = Ti, V, Cr, Mn, Fe, Co, Ni; X = Cl, Br, I)

被引：55

作者：

Yekta, Y. ^{[1
]}

Hadipour, H. ^{[1
]}

Sasioglu, E. ^{[2
]}

Friedrich, C. ^{[3
,4
,5
]}

Jafari, S. A. ^{[6
]}

Bluegel, S. ^{[3
,4
,5
]}

Mertig, I ^{[2
]}

机构：

[1] Univ Guilan, Dept Phys, Rasht 413351914, Iran

[2] Martin Luther Univ Halle Wittenberg, Inst Phys, D-06120 Halle, Saale, Germany

[3] Forschungszentrum Julich, Peter Grunberg Inst, D-52425 Julich, Germany

[4] Forschungszentrum Julich, Inst Adv Simulat, D-52425 Julich, Germany

[5] JARA, D-52425 Julich, Germany

[6] Sharif Univ Technol, Dept Phys, Tehran 111559161, Iran

来源：

PHYSICAL REVIEW MATERIALS | 2021年 / 5卷 / 03期

关键词：

INTRINSIC FERROMAGNETISM; GRAPHENE; CRYSTAL; INSULATOR; MAGNETISM;

D O I：

10.1103/PhysRevMaterials.5.034001

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We calculate the strength of the effective on-site Coulomb interaction (Hubbard U) in two-dimensional transition-metal (TM) dihalides MX2 and trihalides MX3 (M = Ti, V, Cr, Mn, Fe, Co, Ni; X = Cl, Br, I) from first principles using the constrained random-phase approximation. The correlated subspaces are formed from t(2g) or e(g) bands at the Fermi energy. Elimination of the efficient screening taking place in these narrow bands gives rise to sizable interaction parameters U between the localized t(2g) (e(g)) electrons. Due to this large Coulomb interaction, we find U/W > 1 (with the bandwidth W) in most TM halides, making them strongly correlated materials. Among the metallic TM halides in the paramagnetic state, the correlation strength U/W reaches a maximum in NiX2 and CrX3 with values much larger than the corresponding values in elementary TMs and other TM compounds. Based on the Stoner model and the calculated U and J values, we discuss the tendency of the electron spins to order ferromagnetically.

引用

页数：10

共 87 条

[31] Graphene: carbon in two dimensions [J].