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NameMr. Samuel Adegboyega
Organization or InstitutionDEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY, FLORIDA STATE UNIVERSITY
TopicInorganic Chemistry
Title

Investigation of magnetic phase transitions in La1–xCexCo2P2 (x ≤ 0.5)

Author(s)

Samuel Adegboyega, Judith K. Clark, Michael Shatruk

Author Institution(s)

Department of Chemistry and Biochemistry, Florida State University, United States

Abstract

Ternary phosphides LaCo2P2 and CeCo2P2 belong to the ubiquitous ThCr2Si2 structure type but exhibit drastically different magnetic properties. The former shows ferromagnetic (FM) ordering at 132 K,1 while the latter shows antiferromagnetic (AFM) ordering at 440 K.2 Doping Ce into LaCo2P2 was shown to increase the FM ordering temperature and, at higher Ce content, suppress the FM ordering in favor of AFM ordering. The FM-ordered La1–xCexCo2P2 materials (x ≤ 0.5) also show magnetic transitions at lower temperatures, but the nature of those transitions has not been established thus far. In this contribution, we show, first of all, an alternative approach to the synthesis of these materials. While synthesis of La1–xCexCo2P2 in Sn flux frequently leads to an impurity phase with 2:12:7 stoichiometry, we show that this problem can be avoided by performing the synthesis in Bi flux. Further, we focus on magnetic properties of compound with x = 0.5, which shows two consecutive FM transitions. We attribute a higher-temperature transition to ordering of Co 3d moments and a lower-temperature one to ordering of Ce 4f moments. The evolution of structural and magnetic properties in this series will be discussed and further studies will be suggested.

1      Kovnir, K.; Thompson, C. M.; Zhou, H. D.; Wiebe, C. R.; Shatruk, M. Mater. 2010, 22, 1704.

2     Reehuis, M.; Jeitschko, W. Phys. Chem. Solids 1990, 51, 961.