Ferromagnetism and Lattice Distortions in the Perovskite YTiO${}_3$

Abstract

The thermodynamic properties of the ferromagnetic perovskite YTiO${}_3$ are investigated by thermal expansion, magnetostriction, specific heat, and magnetization measurements. The low-temperature spin-wave contribution to the specific heat, as well as an Arrott plot of the magnetization in the vicinity of the Curie temperature $T_C\simeq 27$ K, are consistent with a three-dimensional Heisenberg model of ferromagnetism. However, a magnetic contribution to the thermal expansion persists well above $T_C$, which contrasts with typical three-dimensional Heisenberg ferromagnets, as shown by a comparison with the corresponding model system EuS. The pressure dependences of $T_C$ and of the spontaneous moment $M_s$ are extracted using thermodynamic relationships. They indicate that ferromagnetism is strengthened by uniaxial pressures $\mathbf{p}\parallel \mathbf{a}$ and is weakened by uniaxial pressures $\mathbf{p}\parallel \mathbf{b},\mathbf{c}$ and hydrostatic pressure. Our results show that the distortion along the $a$- and $b$-axes is further increased by the magnetic transition, confirming that ferromagnetism is favored by a large GdFeO${}_3$-type distortion. The c-axis results however do not fit into this simple picture, which may be explained by an additional magnetoelastic effect, possibly related to a Jahn-Teller distortion.

12 pages, 13 figures

References in corpus (6)

• Orbital Physics in the Perovskite Ti Oxides
• Magnetoelastic coupling in RETiO3 (RE = La, Nd, Sm, Gd, Y)
• Lattice Distortion and Magnetism of 3d-$t_{2g}$ Perovskite Oxides
• Optical response of ferromagnetic YTiO_3 studied by spectral ellipsometry
• Importance of In-Plane Anisotropy in the Quasi Two-Dimensional Antiferromagnet BaNi${}_2$V${}_2$O${}_8$
• Heat Capacity and Magnetic Phase Diagram of the Low-Dimensional Antiferromagnet Y${}_2$BaCuO${}_5$

Cited by in corpus (6)

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• Synthesis, Structure and Properties of Tetragonal Sr2M3As2O2 (M3 = Mn3, Mn2Cu and MnZn2) Compounds Containing Alternating CuO2-Type and FeAs-Type Layers
• Uniaxial strain control of bulk ferromagnetism in rare-earth titanates
• Strain-tunable metamagnetic critical endpoint in Mott insulating rare-earth titanates
• Orientation-dependent magnetism and orbital structure of strained YTiO${}_3$ films on LaAlO${}_3$ substrates
• Magnetic resonance study of rare-earth titanates