Spin Frustration and Magnetic Ordering from One-Dimensional Stacking of Cr3 Triangles in TiCrIr2B2

详细信息    查看全文

• 作者：Michael Küpers ; Laura Lutz-Kappelman ; Yuemei Zhang ; Gordon J. Miller ; Boniface P. T. Fokwa
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：June 6, 2016
• 年：2016
• 卷：55
• 期：11
• 页码：5640-5648
• 全文大小：545K
• 年卷期：0
• ISSN：1520-510X

文摘

Spin-frustrated chains of Cr₃ triangles are found in the new metal boride TiCrIr₂B₂ by synergistic experimental and theoretical investigations. Although magnetic ordering is found at 275 K, competing ferro- and anti-ferromagnetic interactions coupled with spin frustration induce a rather small total magnetic moment (0.05 μ_B at 5 T), and density functional theory (DFT) calculations propose a canted, nonlinear magnetic ground-state ordering in the new phase. TiCrIr₂B₂ crystallizes in the hexagonal Ti_1+xOs_2–xRuB₂ structure type (space group P6̅2m, No. 189, Pearson symbol hP18). The structure contains trigonal planar B₄ boron fragments with B–B distances of 1.76(3) Å alternating along the c-direction with Cr₃ triangles with intra- and intertriangle Cr–Cr distances of 2.642(9) and 3.185(1) Å, respectively. Magnetization measurements of TiCrIr₂B₂ reveal ferrimagnetic behavior and a large, negative Weiss constant of −750 K. DFT calculations demonstrate a strong site preference of Cr for the triangle sites, as well as magnetic frustration due to indirect anti-ferromagnetic interactions within the Cr₃ triangles.