Structure, Magnetism, and Colossal Magnetoresistance (CMR) of the Ternary Transition Metal Solid Solution Ca14-xEuxMnSb<
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- 作者：Hyungrak Kim ; Marilyn M. Olmstead ; Peter Klavins ; David J. Webb ; and Susan M. Kauzlarich
- 刊名：Chemistry of Materials
- 出版年：2002
- 出版时间：August 2002
- 年：2002
- 卷：14
- 期：8
- 页码：3382 - 3390
- 全文大小：268K
- 年卷期：v.14,no.8(August 2002)
- ISSN：1520-5002
文摘
The solid solution of the ternary transition metal Zintl phase Ca14-xEuxMnSb11 (0 < x <14) has been prepared by heating a mixture of stoichiometric amounts of the elements in atwo-zone furnace with Thigh = 1100 
C and Tlow = 1050 C. The ternary transition metalcompounds crystallize in the tetragonal space group I41/acd and are isostructural with theZintl compound Ca14AlSb11. The lattice parameters of the Ca14-xEuxMnSb11 compoundslinearly increase with increasing Eu substitution for Ca. The Eu atoms preferentially occupythe Ca(2) site first and subsequently occupy Ca(4), Ca(1), and Ca(3), in order, among thefour crystallographically inequivalent Ca sites. Temperature-dependent magnetic susceptibility measurements of the solid solution reveal that Eu replacement for Ca induces complexmagnetic interactions in the compound, from simple ferromagnetic interactions for Ca14MnSb11 to ferrimagnetic interactions for Eu14MnSb11, because of the Eu2+(4f 7) magneticmoment. The paramagnetic Curie temperature of the Ca14-xEuxMnSb11 compounds showsan interesting change with varying x, and the magnetic easy axis gradually changes in thesolid solution from perpendicular (for Ca14MnSb11) to parallel (for Eu14MnSb11) to the crystalc axis. The electrical transport properties of the Ca14-xEuxMnSb11 (x = 0, 3, 11) compoundsshow a close relation to their magnetic properties and are compared to the previous resultsfor Ca14-xEuxMnSb11 (x = 13, 14). The influence of Eu doping on the structural and physicalproperty of Ca14-xEuxMnSb11 is discussed in terms of the site preferences of Eu for the fourdifferent Ca sites.
C and Tlow = 1050 C. The ternary transition metalcompounds crystallize in the tetragonal space group I41/acd and are isostructural with theZintl compound Ca14AlSb11. The lattice parameters of the Ca14-xEuxMnSb11 compoundslinearly increase with increasing Eu substitution for Ca. The Eu atoms preferentially occupythe Ca(2) site first and subsequently occupy Ca(4), Ca(1), and Ca(3), in order, among thefour crystallographically inequivalent Ca sites. Temperature-dependent magnetic susceptibility measurements of the solid solution reveal that Eu replacement for Ca induces complexmagnetic interactions in the compound, from simple ferromagnetic interactions for Ca14MnSb11 to ferrimagnetic interactions for Eu14MnSb11, because of the Eu2+(4f 7) magneticmoment. The paramagnetic Curie temperature of the Ca14-xEuxMnSb11 compounds showsan interesting change with varying x, and the magnetic easy axis gradually changes in thesolid solution from perpendicular (for Ca14MnSb11) to parallel (for Eu14MnSb11) to the crystalc axis. The electrical transport properties of the Ca14-xEuxMnSb11 (x = 0, 3, 11) compoundsshow a close relation to their magnetic properties and are compared to the previous resultsfor Ca14-xEuxMnSb11 (x = 13, 14). The influence of Eu doping on the structural and physicalproperty of Ca14-xEuxMnSb11 is discussed in terms of the site preferences of Eu for the fourdifferent Ca sites.