Electrical Transport Property of A-site La Doped of Sr2IrO4

doi:10.15541/jim20170568

Abstract

Abstract:

The physics of electric transport in iridate Sr₂IrO₄ has been a long term controversial issue in the field of 5d oxides. A series of single crystal samples (Sr_1-_xLa_x)₂IrO₄ were prepared by flux method, and their electrical transport properties were investigated. The results reveal that the sample shows metallic transport at x≥0.03. A close examination of the transport data reveals drastic modulation for the conduction mechanism upon La-doping. For the non-doped sample, three-dimensional Mott variable range hopping conduction is respectively identified at T>140 K and 40 K<T<80 K, and thermal activation conduction is revealed at 80 K<T<140 K. For the doped sample, the Mott variable range hopping conduction is only found at T<90 K, and the activation energy is revealed to decrease with the La-doping content increasing. In addition, the localization length of the doped samples is found to be much larger than the Ir-O bond length, which may due to delocalization effect of the carriers in the systems.

Key words: Sr₂IrO₄ Mott insulator, electric transport, thermal activation, 3D variable range hopping

CLC Number:

O513

DUAN Tian-Ci, WANG Hao-Wen, WANG Wei, PEI Ling, HU Ni. Electrical Transport Property of A-site La Doped of Sr₂IrO₄[J]. Journal of Inorganic Materials, 2018, 33(9): 1001-1005.

Figures/Tables 4

Fig. 1 XRD patterns of (Sr1-xLax)2IrO4(x=0 ,0.01, 0.02, 0.03, 0.05)

Fig. 2 ρab vs T plots of (Sr1-xLax)2IrO4(x=0, 0.01, 0.02, 0.03, 0.05)From top to bottom: x=0, 0.01, 0.02, 0.03, 0.05, respectively Inset shows detail of the (Sr1-xLax)2IrO4(x=0.03, 0.05)

Fig. 3 lnρab vs T-1 and lnρab vs T-1/4 plot of (Sr1-xLax)2IrO4(x=0, 0.01, 0.02, 0.03, 0.05) Upper level from left to right (a)-(e); lower lever from left to right (a1)~(e1)Straight lines (a)~(e) are fitting of data following Eq. (1), straight lines (a1)-(e1) are fitting of data following Eq.(2), with vertical arrows mark for the corresponding temperature

Table 1 Fitting parameters to the thermal activation model and 3D Mott variable range hopping model for single crystal (Sr1-xLax)2IrO4 (x=0, 0.01, 0.02, 0.03, 0.05)

x	Δ/meV	T_M/(×10⁴, K)	(R_M/a)/K^-1/4	a/nm	E_M/meV
0	84.4	?39	9.4 T^1/4	0.320	0.54 T^3/4
0	84.4	6561	33.8/T^1/4	0.058	1.94 T^3/4
0.01	6.4	?0.0016	0.75 T^1/4	9.300	0.04 T^3/4
0.01	6.4	2.8	4.8/T^1/4	0.770	0.28 T^3/4
0.02	6.2	0.45	3.1/T^1/4	1.430	0.18 T^3/4
0.03	1.5	0.0028	0.9/T^1/4	7.790	0.05 T^3/4
0.05	2.1	0.0092	1.2/T^1/4	5.310	0.07 T^3/4

References 24

[1]	CAO G, QI T F, LI L, et al. Evolution of magnetism in single- crystal honeycomb iridates. Phys. Rev. B, 2013, 88(22): 220414-1-8.
[2]	KIM B J, OHSUMI H, KOMESU T,et al. Phase-sensitive observation of a spin-orbital Mott state in Sr2IrO4. Science, 2009, 323(5919): 1329-1332.
[3]	WANG F, SENTHIL T.Twisted Hubbard model for Sr2IrO4: magnetism and possible high temperature superconductivity.Phys. Rev. Lett., 2011, 106(13): 186-197.
[4]	WATANABE H, SHIRAKAWA T, YUNOKI S. Monte Carlo study of an unconventional superconducting phase in iridium oxide Jeff=1/2 Mott insulators induced by carrier doping. Phys. Rev. Lett., 2013, 110(2): 027002-1-5.
[5]	MENG Z Y, KIM Y B, KEE H Y. Odd-parity triplet superconducting phase in multi-orbital materials with a strong spin-orbit coupling: application to doped Sr2IrO4. Phys. Rev. Lett., 2014, 113(17): 177003-1-5.
[6]	LU C L, QUINDEAU A, DENIZ H, et al. Crossover of conduction mechanism in Sr2IrO4 epitaxial thin films. Appl. Phys. Lett., 2014, 105(8): 082407-1-5.
[7]	YAN Y J, REN M Q, XU H C, et al. Electron-doped Sr2IrO4: an analogue of hole-doped cuprate superconductors demonstrated by scanning tunneling microscopy. Phys. Rev. X, 2015, 5(4): 041018- 1-7.
[8]	CAO G, XIN Y, ALEXANDER C S, et al. Anomalous magnetic and transport behavior in the magnetic insulator Sr3Ir2O7. Phys. Rev. B, 2002, 66(21): 214412-1-7.
[9]	FUJIOKA J, OKAWA T, YAMAMOTO A, et al. Correlated Dirac semi-metallic state with unusual positive magnetoresistance in strain-free perovskite SrIrO3. Phys. Rev. B, 2017, 95(12): 121102-1-5.
[10]	LU C L, DONG S, QUINDEAU A, et al. Dual gate control of bulk transport Dual gate control of bulk transport and magnetism in the spin-orbit insulator Sr2IrO4. Phys. Rev. B, 2015, 91(10): 104401-1-9.
[11]	KITTAKA S, TANIGUCHI H, YONEZAWA S, et al. Higher-Tc superconducting phase in Sr2RuO4 induced by uniaxial pressure. Phys. Rev. B, 2010, 81(18): 180510-1-4.
[12]	CAI X, YING Y A, STALEY N E, et al. Unconventional quantum oscillations in mesoscopic rings of spin-triplet superconductor Sr2RuO4. Phys. Rev. B, 2013, 87(8): 081104-1-5.
[13]	GE M, TAN S, SHAO J, et al. Interaction between 3d-, 4d-and 5d-electron in Sr2Ir1-x(Ru,Ti)xO4. J. Magn. Magn. Mater., 2014, 369: 223-227.
[14]	KIM B J, JIN H, MOON S J, et al. Novel Jeff =1/2 Mott state induced by relativistic spin-orbit coupling in Sr2IrO4. Phys. Rev. Lett., 2008, 101(7): 076402-1-4.
[15]	CAO G, BOLIVAR J, MCCALL S,et al. Weak ferromagnetism, metal-to-nonmetal transition, and negative differential resistivity in single-crystal Sr2IrO4. Phys. Rev. B, 1998, 57(18): R11039-R11042.
[16]	BAHR S, ALFONSOV A, JACKELI G, et al. Low-energy magnetic excitations in the spin-orbital Mott insulator Sr2IrO4. Phys. Rev. B, 2014, 89(18): 180401-1-5.
[17]	CHEN X, HOGAN T, WALKUP D, et al. Influence of electron doping on the ground state of Influence of electron doping on the ground state of (Sr1-xLax)2IrO4. Phys. Rev. B, 2015, 92(7): 075125-1-11.
[18]	GE M, QI T F, KORNETA O B,et al. Lattice-driven magnetoresistivity and metal-insulator transition in single-layered iridates. Phys. Rev. B, 2011, 84(10): 3382-3391.
[19]	QI T F, KORNETA O B, LI L, et al. Spin-orbit tuned metal-insulator transitions in single-crystal Sr2Ir1-xRhxO4 (0≤x≤1). Phys. Rev. B, 2012, 86(12): 125105-1-6.
[20]	YUAN S J, ASWARTHAM S, TERZIC J, et al. From Jeff=1/2 insulator to p-wave superconductor in single-crystal Sr2Ir1-xRuxO4 (0 ≤ x ≤ 1). Phys. Rev B, 2015, 92(24): 245103-1-6.
[21]	CHENG L, WANG L L, PU S J,et al. Structure and electric transport properties of the spin ladder compound Sr14(Cu0.97M0.03)24O41, 2010, 59(2): 1155-1162.
[22]	KLEIN Y, TERASAKI I.Insight on the electronic state of Sr2IrO4 revealed by cationic substitutions.J. Phys.: Condens. Matter., 2008, 20(29): 2123-2131.
[23]	MOTT N F.Conduction in glasses containing transition metal ions.J. Non-Cryst. Solids, 1968, 1(1): 1-17.
[24]	ROSENBAUM R.Crossover from Mott to Efros-Shklovskii variable- range-hopping conductivity in In xOy films. Phys. Rev. B, 1991, 44(8): 3599-3603.

Electrical Transport Property of A-site La Doped of Sr₂IrO₄

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