Optimization of Electrode Material and Connecting Process for Mg-Si-Sn Based Thermoelectric Device

doi:10.15541/jim20140623

Abstract

Abstract:

Metal (Ni, Cu, Ag, Al) electrode was connected with Mg-Si-Sn based thermoelectric materials by Spark Plasma Sintering (SPS) process. Microstructure of interface, sintering process and transport properties, including electrical conductivity, thermal conductivity and thermal expansion coefficient, of electrode materials were investigated. The results showed that composites of Ni-Al /Al (60:40) and Cu-Al/Cu (45:55) displayed high electrical conductivity, high thermal conductivity and suitable thermal expansion coefficient to Mg-Si-Sn based materials. It is indicated that the two composites have potential to be used as good electrode materials for, and to be connected by SPS sintering to, Mg-Si-Sn based materials.

Key words: Mg-Si-Sn, thermoelectric material, electrode material

CLC Number:

TB34

CHEN Geng, LIU Tao-Xiang, TANG Xin-Feng, SU Xian-Li, YAN Yong-Gao. Optimization of Electrode Material and Connecting Process for Mg-Si-Sn Based Thermoelectric Device[J]. Journal of Inorganic Materials, 2015, 30(6): 639-646.

Figures/Tables 10

Fig. 1 Back scattering images and line profiles of the interface between Ni and Mg-Si-Sn by EMPA (a-b) BSE photographs of the joint between Ni and Mg-Si-Sn; (c) BSE photographs of Mg-Si-Sn; (d-e) Line profiles of the joint Arrows point to the cracks

Fig. 2 Temperature dependence of CTE for metal electrodes and Mg-Si-Sn

Fig. 3 Pictures of samples sintered by one step SPS (a) Sectional view of Cu/Mg-Si-Sn; (b) Sectional view of Ag/Mg-Si- Sn; (c) Mg-Si-Sn of Al/Mg-Si-Sn

Fig. 4 Back scattering images and line profiles of the interface between Cu and Mg-Si-Sn by EMPA (a-c) Holding for 10 min and with cooling rate of 20 K/min; (a) BSE photograph; (b-c) line profiles; Inset photograph in (a) is BSE photograph of the joint with rapid cooling process; (d-f) Holding for 20 min and with cooling rate of 10 K/min; (d) BSE photograph; (e-f) line profiles

Fig. 5 Back scattering images and line profiles of the interface between Ag and Mg-Si-Sn by EMPA (a-c) Holding for 5 min with cooling rate of 20 K/min; (a) BSE photograph; (b-c) Line profiles; Circles represent the region of Ag and Mg rich area; (d-f) Holding for 10 min with cooling rate of 10 K/min; (d) BSE photograph; (e-f) Line profiles

Fig. 6 Back scattering images and line profiles of the interface between Al and Mg-Si-Sn by EMPA (a-c) Holding for 5 min with cooling rate of 20 K/min; (a) BSE photograph; (b-c) Line profiles (d-f) Holding for 10 min with cooling rate of 10 K/min; (d) BSE photograph; (e-f) Line profiles

Fig. 7 XRD patterns of raw materials.

Fig. 8 Temperature dependence of basic physical properties for alloy material

Fig. 9 Physical properties as a function of temperature for Ni-Al/Al

Fig. 10 Physical properties as a function of temperature for Cu-Al/Cu

References 22

[1]	VINING C B.Chapter 23 Thermoelectric Properties of Silicides. CRC handbook of thermoelectrics. Raton London New York Washington, D C: CRC Press LLC, 1995: 277-285.
[2]	HAN Z M, ZHANG X, LU Q M, et al.Preparation and thermoelectric properties of (Mg2Si1-xSbx)0.4-(Mg2Sn)0.6 alloys.Journal of Inorganic Materials, 2012, 27(8): 822-826.
[3]	ZAITSEV V K, FEDOROV M I, GURIEVA E A, et al.Highly effective Mg2Si1-xSnx thermoelectrics.Physical Review B, 2006, 74(4): 045207.
[4]	NODA Y, KON H, FURUKAWA Y, et al.Preparation and thermoelectric properties of Mg2Si1-xGex (x=0-0.4) solid solution semiconductors. Materials Transactions, JIM, 1992, 33(9): 845-850.
[5]	SONG R B, LIU Y Z, AIZAWA T.Solid state synthesis and thermoelectric properties of Mg-Si-Ge system.Journal of Materials Science & Technology, 2005, 21(5): 618-622.
[6]	FEDOROV M I, ZAITSEV V K, EREMIN I S, et al.Transport properties of Mg2X0.4Sn0.6 solid solutions (x=Si, Ge) with p-type conductivity.Physics of the Solid State, 2006, 48(8): 1486-1490.
[7]	SAKAMOTO T, IIDA T, MATSUMOTO A, et al.Thermoelectric characteristics of a commercialized Mg2Si source doped with Al, Bi, Ag and Cu.Journal of Electronic Materials, 2010, 39(9): 1708-1713.
[8]	LIU W, TANG X F, LI H, et al.Optimized thermoelectric properties of Sb-doped Mg2(1+z)Si0.5-ySn0.5Sby through adjustment of the Mg content.Chemistry of Materials, 2011, 23(23): 5256-5263.
[9]	TAN X J, LIU W, LI H, et al.Multiscale calculations of thermoelectric properties of n-type Mg2Si1-xSnx solid solutions.Physical Review B, 2012, 85(20): 205212.
[10]	LIU W.Optimization of Thermoelectric Properties of n-type Mg2Si1-xSnx Based Materials Through Doping As Well As the Adjustment and Cotrol of Band Structure. Wuhan: Wuhan University of Technology. PhD Thesis, 2012: 28.
[11]	SAKAMOTO T, IIDA T, TAGUCHI Y, et al.Examination of a thermally viable structure for an unconventional uni-leg Mg2Si thermoelectric power generator.Journal of Electronic Materials, 2012, 41(6): 1429-1435.
[12]	NEMOTO T, IIDA T, SATO J, et al. Power generation characteristics of Mg2Si uni-leg thermoelectric generator. Journal of Electronic Materials, 2012, 41(6): 1312-1316.
[13]	SAKAMOTO T, IIDA T, KUROSAKI S, et al.Thermoelectric behavior of Sb- and Al-doped n-type Mg2Si device under large temperature differences.Journal of Electronic Materials, 2011, 40(5): 629-634.
[14]	SAKAMOTO T, IIDA T, FUKUSHIMA N, et al.Thermoelectric properties and power generation characteristics of sintered undoped n-type Mg2Si.Thin Solid Films, 2011, 519(24): 8528-8531.
[15]	SAKAMOTO T, IIDA T, HONDA Y, et al.The use of ransition-metal silicides to reduce the contact resistance between the lectrode and sintered n-type Mg2Si.Journal of Electronic aterials, 2012, 41(6): 1805-1810.
[16]	NEMOTO T, IIDA T, SATO J, et al.Characteristics of a pin-fin structure thermoelectric uni-leg device using a commercial n-type Mg2Si source.Journal of Electronic Materials, 2010, 39(9): 1572-1578.
[17]	FAN J F, CHEN L D, BAI S Q, et al. Joining of Mo to CoSb3 by spark plasma sintering by inserting a Ti interlayer.Materials Letters, 2004, 58: 3876-3878.
[18]	WOJCIECHOWSKI K T, ZYBALA R, MANIA R.High temperature CoSb3-Cu junctions.Microelectronics Reliability, 2011, 51(7): 1198-1202.
[19]	ZHAO D G, GENG H R, TENG X Y.Fabrication and reliability evaluation of CoSb3/W-Cu thermoelectric element.Journal of Alloys and Compounds, 2012, 517: 198-203.
[20]	ZHAO D G, LI X Y, HE L, et al.High temperature reliability evaluation of CoSb3/electrode thermoelectric joints.Intermetallics, 2009, 17(3): 136-141.
[21]	ZHAO D G, LI X Y, HE L, et al.Interfacial evolution behavior and reliability evaluation of Cosb3/Ti/Mo-Cu thermoelectric joints during accelerated thermal aging.Journal of Alloys and Compounds, 2009, 477(1/2): 425-431.
[22]	ZHAO D G, Li X Y, JIANG W, et al.Fabrication of CoSb3 /MoCu thermoelectric joint by one-step SPS and evaluation.Journal of Inorganic Materials, 2009, 24(3): 545-548.