Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · cond-mat/0307513

Electric Field Effects on the Diffuse Scattering in PZN-8%PT

P. M. Gehring·K. Ohwada·G. Shirane
View original source ↗Read source document ↗Export metadata ↓

Abstract

We report measurements of the neutron diffuse scattering from a single crystal of the relaxor ferroelectric Pb(Zn_1/3Nb_2/3)O_3 doped with 8% PbTiO_3 (PZN-8%PT) for temperatures 100 K < T < 530 K and electric fields 0 kV/cm < E < 10 kV/cm. The diffuse scattering is strongly suppressed transverse to the (003) Bragg peak at 400 K for E = 2 kV/cm applied along the [001] direction. However, no change in the diffuse scattering is observed transverse to (300), even for field strengths up to 10 kV/cm. Thus the application of an external electric field in the tetragonal phase does not produce a macroscopically polarized state. This unusual behavior can be understood within the context of the Hirota et al. phase-shifted polar nanoregion (PNR) model of the relaxor diffuse scattering, since an electric field E oriented parallel to [001] would remove the shift of the nanoregions along [001] while preserving those along the orthogonal [100] direction.

Explore related subjects

cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P. M. Gehring, K. Ohwada, G. Shirane. 2003-07-27. Electric Field Effects on the Diffuse Scattering in PZN-8%PT. https://doi.org/10.1103/physrevb.70.014110

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Impact of electron--spin coupling on exchange coupling parameters: a nonperturbative approach

Exchange coupling parameters $J_{ij}$ in the Heisenberg model are crucial for describing magnetic behavior at the atomic level. In magnetic materials, spin fluctuations can be accompanied by a self-consistent electronic response, i.e., electron--spin coupling in the sense of electronic feedback to finite spin rotations. However, the quantitative importance of this coupling in extracting reliable $J_{ij}$ has not been fully clarified. Here, using fully self-consistent, nonperturbative evaluations, we show that finite-angle spin rotations induce such electronic feedback and quantify how strongly it renormalizes the extracted $J_{ij}$. We examine systems of both fundamental and practical interest, including perovskite SrMnO$_3$, Nd-based permanent-magnet compounds (Nd$_2$Fe$_{14}$B and Nd$_2$Co$_{14}$B), and elemental 3$d$ transition metals. The nonperturbative approach yields exchange couplings that remain consistent over a wide range of rotation angles. Moreover, when the sampled configurations represent the magnetic disorder near the transition, spin models parameterized in this way give reasonable agreement with experimental magnetic phase-transition temperatures. Overall, our results demonstrate the quantitative impact of electron--spin coupling on the exchange coupling parameters $J_{ij}$ and provide a nonperturbative route to effective $J_{ij}$ for a specified regime of magnetic disorder.

cond-mat.mtrl-sci↗
arXiv2026

Benchmarking and advancing machine-learning interatomic potentials for 3C-SiC across equilibrium and extreme conditions

Several machine-learning interatomic potentials (MLIPs) have been developed for cubic silicon carbide (3C-SiC). Here, we benchmark seven existing MLIPs against a common set of structural, thermal, defect, radiation-damage, disordered-phase, and computational-performance tests. We also introduce two complementary MLIPs trained on DFT-labeled crystalline, liquid, amorphous, and defective configurations. TGAP, a Gaussian approximation potential based on the \verb|soap_turbo| descriptor, provides consistently high accuracy across the sampled configurational space. MTP, a custom moment tensor potential, retains good accuracy across these regimes while offering substantially lower computational cost, GPU acceleration, and access to multi-million-atom simulations. As an application-level test, both potentials remain stable in displacement cascades spanning short-range repulsion, transient disorder, and recrystallization. Overall, MTP emerges as a particularly strong accuracy--cost compromise for large-scale and strongly non-equilibrium simulations of 3C-SiC.

cond-mat.mtrl-sci↗
arXiv2026

Loss of altermagnetic order and smooth restoration of Kramers' spin degeneracy with increasing temperature in CrSb and MnTe

We describe how thermally induced spin fluctuations modify the electronic structures of two prototypical altermagnets, CrSb and MnTe, via application of the disordered local moment picture. For both materials, our self-consistent, ab initio calculations demonstrate that local magnetic moments persist on Cr and Mn atoms in their paramagnetic states, necessitating a spin-polarised description of the electronic structure even above the Néel temperature, $T_\mathrm{N}$. Moreover, Kramers' spin degeneracy, which is broken for both materials in their altermagnetic ground states, is shown to be smoothly restored - on the average - as the local moments thermally disorder. In metallic CrSb, this occurs at temperatures well below $T_\mathrm{N}$ and the signature effects of its altermagnetism are lost as the magnetic disorder induces heavy smearing of strongly dispersive electronic states around the Fermi energy. By contrast, in semiconducting MnTe, with its band gap largely unaffected by magnetic disorder, the spin degeneracy only returns at temperatures close to and above $T_\mathrm{N}$. We quantify the temperature dependence of the altermagnetic order parameter and the underlying electronic structures of both materials, with implications for their spin transport and spectroscopic properties.

cond-mat.mtrl-sci↗