Magnetic properties of (DyxLa1-x)2Ti2O7 |
| R. Jackoa, K. Csachb, G. Pristášb, M. Mihalik Jr.b, M. Zentkováb, M. Mihalikb
aUSSE Research & Development, U.S. Steel Košice s.r.o., 044 54 Košice, Slovakia bInstitute of Experimental Physics SAS, Watsonova 47, 04001 Košice, Slovakia |
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| In our paper we focus on magnetic properties of (DyxLa1-x)2Ti2O7 system, which may combine ferroelectric properties of La2Ti2O7 with magnetic structure and ferroelectricity of spin frustrated system of Dy2Ti2O7. Despite of the fact that SEM indicates homogeneous samples with expected chemical composition, XRPD measurements revealed the limited solubility of La or Dy dopant in parent compounds, and coexistence of two crystal structures - pyrochlore cubic Fd̅3m and orthorhombic Pna21 in intermediate concentration range between x=0.68 and x=0.32. The substitution of Dy by La expands the crystal lattice of both crystal structures. The AC susceptibility measurements revealed that spin freezing temperature Tf shifts to higher temperature with La substitution and provided an evidence either of new magnetic phase with Pna21 crystal structure or creation of new dynamical behaviour in Fd̅3m phase below x=0.68 in the range between Ti and Tf. The frequency and magnetic field dependences on samples with pyrochlore structure resemble features typical for Dy2Ti2O7. The heat capacity measurements indicate that the temperature of transition to spin ice ground state at Ti is not affected by La substitution for concentration with x≤0.32. |
DOI:10.12693/APhysPolA.137.997 topics: crystal structure, ferroelectric compound, spin ice, AC susceptibility, heat capacity |