A new density-modification procedure extending the application of the recent |ρ|-based phasing algorithm to larger crystal structures
13 July 2021
The incorporation of the new peakness-enhancing fast Fourier transform compatible ipp procedure (ipp = inner-pixel preservation) into the recently published SM algorithm based on |ρ| [Rius (2020). Acta Cryst A76, 489–493] improves its phasing efficiency for larger crystal structures with atomic resolution data. Its effectiveness is clearly demonstrated via a collection of test crystal structures (taken from the Protein Data Bank) either starting from random phase values or by using the randomly shifted modulus function (a Patterson-type synthesis) as initial ρ estimate.
It has been found that in the presence of medium scatterers (e.g. S or Cl atoms) crystal structures with 1500 × c atoms in the", 'Navigator')" style="text-decoration: none; color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px;">unit cell (c = number of centerings) can be routinely solved. In the presence of strong scatterers like Fe, Cu or Zn atoms this number increases to around 5000 × c atoms. The implementation of this strengthened SM algorithm is simple, since it only includes a few easy-to-adjust parameters.
Hits: 343
Oxides for new-generation electronics

A new density-modification procedure extending the application of the recent |ρ|-based phasing algorithm to larger crystal structures

Jordi Rius* and Xavier Torrelles

Acta Cryst. (2021). A77339-347

Also at ICMAB

  • Giant Tuning of Electronic and Thermoelectric Properties by Epitaxial Strain in p-Type Sr-Doped LaCrO3 Transparent Thin Films

    14 September 2021 124 hit(s) Oxides
    The impact of epitaxial strain on the structural, electronic, and thermoelectric properties of p-type transparent Sr-doped LaCrO3 thin films has been investigated. For this purpose, high-quality fully strained La0.75Sr0.25CrO3 (LSCO) epitaxial thin films were grown by molecular beam epitaxy on three different (pseudo)cubic (001)-oriented perovskite oxide substrates: LaAlO3, (LaAlO3)0.3(Sr2AlTaO6)0.7, and DyScO3. The lattice mismatch between the LSCO films and the substrates induces in-plane strain ranging from −2.06% (compressive) to +1.75% (tensile).
  • Magnetocapacitance effect and magnetoelectric coupling in type-II multiferroic HoFeWO 6

    10 September 2021 159 hit(s) Oxides
    We have investigated the multiferroicity and magnetoelectric (ME) coupling in HoFeWO6. With a noncentrosymmetric polar structure (space group Pna21) at room temperature, this compound shows an onset of electric polarization with an antiferromagnetic ordering at the Néel temperature (TN) of 17.8 K. The magnetic properties of the polycrystalline samples were studied by DC and AC magnetization and heat capacity measurements.
  • Insights into the atomic structure of the interface of ferroelectric Hf0.5Zr0.5O2 grown epitaxially on La2/3Sr1/3MnO3

    31 August 2021 273 hit(s) Oxides
    Epitaxial growth of Hf0.5Zr0.5O2 (HZO) thin films allows for the stabilization of the metastable orthorhombic phase with robust ferroelectric properties. So far, the ferroelectric phase is most commonly stabilized on perovskite substrates upon insertion of a buffer layer of La2/3Sr1/3MnO3 (LSMO).
  • Symmetry mode analysis of distorted polar/nonpolar structures in A-site ordered SmBaMn2O6 perovskite

    13 August 2021 290 hit(s) Oxides
    We present a comprehensive structural study of the charge-orbital ordering and magnetic phase transitions observed in the A-site ordered SmBaMn2O6 perovskite combining synchrotron radiation x-ray powder diffraction and symmetry-adapted modes analysis. InSmBaMn2O6, successive phase transitions in charge, spin, and lattice degrees of freedom take place with decreasing temperature at TCO1≈380K,TCO2≈190K, and TN≈250K.
  • Thickness effect on ferroelectric properties of La-doped HfO2 epitaxial films down to 4.5 nm

    10 August 2021 321 hit(s) Oxides
    Stabilization of the orthorhombic phase of HfO2 with La allows very high polarization and endurance. However, these properties have not been confirmed yet in films having thickness of less than 10 nm. We have grown (111)-oriented La (2 at%) doped epitaxial HfO2 films on SrTiO3(001) and Si(001) substrates, and we report on the thickness dependence of their ferroelectric properties.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.