Neutron diffraction and NQR study of the intermediate turn angle phase formed during AFI to AFII reordering in YBa{sub 2}Cu{sub 3{minus}x}Al{sub x}O{sub 6+{delta}}

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.940· OSTI ID:531839

Brecht, E; Schmahl, W W; Fuess, H ^[1]; Schmenn, S; Luetgemeier, H ^[2]; Andersen, N H; Lebech, B ^[3]; Wolf, T ^[4]

---

1. Fachbereich Materialwissenschaft, Fachgebiet Strukturforschung, Technische Hochschule Darmstadt, Petersenstrasse 23, D-64287 Darmstadt (Germany)
2. Forschungsanlage Juelich, Institut fuer Festkoerperforschung 4, P.O. Box 1913, D-52425 Juelich (Germany)
3. Riso/ National Laboratory, Department of Solid State Physics, P.O. Box 49, DK-4000 Roskilde (Denmark)
4. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, P.O. Box 3640, D-76021 Karlsruhe (Germany)

The reordering mechanism from the antiferromagnetic phase AFI to the antiferromagnetic phase AFII in an oxygen-deficient YBa{sub 2}Cu{sub 2.94}Al{sub 0.06}O{sub 6+{delta}} single crystal with an oxygen content {delta}=0.18 in the Cu(1) layer has been studied by neutron diffraction and nuclear quadrupole resonance (NQR). The crystal orders magnetically from the paramagnetic state to the antiferromagnetic AFI state at the N{acute e}el temperature T{sub N}=403 K with an empirical critical exponent of {beta}=0.26. Reordering to the antiferromagnetic AFII state sets in at T{sub 2}=12 K. In both the AFI and AFII phases the ordered magnetic moments on the Cu(2) lattice sites are identical and take a value of {l_angle}S{r_angle}{sub Cu(2)}{approx}0.56{mu}{sub B}; no ordered moment is found on the Cu(1) lattice sites. From the temperature dependence of the Cu(1) NQR spectrum, the magnetic hyperfine field at Cu(1) sites is found to vary continuously as a function of temperature. This result indicates unequivocally that the AFI{leftrightarrow}AFII reordering takes place via a noncollinear intermediate turn angle phase AFI{circle_plus}II. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 531839
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 2 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
ANTIFERROMAGNETIC MATERIALS
ANTIFERROMAGNETISM
BARIUM OXIDES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
HYPERFINE STRUCTURE
MAGNETIC MOMENTS
NEEL TEMPERATURE
NEUTRON DIFFRACTION
NUCLEAR QUADRUPOLE RESONANCE
STOICHIOMETRY
YTTRIUM OXIDES