Supplementary materials for paper titled as: Metal-Semiconductor-Transition
observed in Bi2Ca(Sr, Ba)2Co2O8+δ Single Crystals
Song-Tao Dong1,3, Bin-Bin Zhang1, Lun-Yong Zhang1, Y. B. Chen2*, Shu-Hua Yao1*,
Jian Zhou1, Shan-Tao Zhang1, Zhen-Bin Gu1, and Yan-Feng Chen1
1
National Laboratory of Solid State Microstructures and Department of Material
Science and Engineering, Nanjing University, Nanjing, 210093, P. R. China
2
National Laboratory of Solid State Microstructures and Department of Physics and
National Laboratory of Solid State Microstructures, Nanjing University, Nanjing，
210093, P. R. China
3
Institute of Material Science and Engineering, Jiangsu University of Science and
Technology, Zhenjiang 212003, China
In this supplementary material, we summarized the experimental details, and
some fitted parameters of temperature-dependent resistance of Bi2AE2Co2O8+δ
(AE=Ca, Sr and Ba).
Single crystals of Bi2AE2Co2O8+δ (AE=Ca, Sr and Ba) were grown by the flux
method using K2CO3-KCl as solvent. The single-crystal synthesis includes two steps:
firstly, polycrystalline samples were synthesized by a solid-state reaction method;
secondly prepared polycrystalline samples and a K2CO3-KCl mixture were heated to
1103 K and held at this temperature for 24 h. After a growth run of 7 days, many
shiny and thin plate-like crystals were separated from solvent with distilled water. The
crystal structure of Bi2AE2Co2O8+δ (AE=Ca, Sr and Ba) single crystals was
characterized by using X-ray powder diffraction (XRD, Ultima III Rugaku) with
Cu-Kα radiation as an X-ray source. The composition of single crystals was
determined by energy dispersive spectroscopy (EDS) in a scanning electron
microscope (SEM, FEI-Quantum) with standard reference sample. The X-ray
photoemission spectroscopy (XPS) spectra of the core-levels of Co ion and valance
band in these samples were collected using a Thermo Scientific K-Alpha instrument.
Electron microprobe analysis was done in JXA-8230 instrument (JEOL Inc.) The
temperature-dependent resistance/magnetoresistance was measured by the standard
four-probe technique on a physical property measurement system (PPMS, Quantum
Design Inc.).
The fitted parameters of temperature-dependent resistance of Bi2AE2Co2O8+δ (N.
A means not applied) are summarized in table. 1. The corresponding discussion can
be found in the main text.
Table 1 The fitted parameters of temperature-dependent resistance of Bi2AE2Co2O8+δ
(N. A means not applied).
 0 ( m cm )
c1 ( m cm / K )
c2 ( m cm )
T0 ( K 3 )
Bi2Ca2Co2O8+δ
7.027×10-3
2.78×10-5
2.12×10-4
15.86
Bi2Sr2Co2O8+δ
3.47×10-4
6.35×10-6
1.65×10-5
10.39
Bi2SrBaCo2O8+δ
4.07×10-2
1.18×10-6
6.11×10-5
N. A
Bi2Ba2Co2O8+δ
1.09×10-4
2.28×10-6
N. A
N. A
1