TY - JOUR
T1 - Compounds Containing Tetragonal Cu2+ Complexes: Is the dx2–y2–d3z2–r2 Gap a Direct Reflection of the Distortion?
AU - García-Fernández, Pablo
AU - Barriuso, María Teresa
AU - García Lastra, Juan Maria
AU - Moreno, Miguel
AU - Aramburu, José Antonio
PY - 2013
Y1 - 2013
N2 - It is widely assumed that the gap, Δ, between dx2–y2 and d3z2–r2 orbitals in fluorides and oxides containing tetragonal Cu2+ or Ag2+ complexes directly reflects the tetragonal distortion in the MX6 complex (M = d9 ion; X = F–, O2–). This assumption on that relevant quantity is shown to be not correct through the study of pure K2CuF4-, KCuF3-, and Cu2+-doped KZnF3 and K2ZnF4 model compounds. Indeed, ab initio calculations prove that Δ in these insulating materials also depends on the internal electric field created by the rest of lattice ions on active electrons confined in a given CuF64– complex. This internal field, especially important for layered compounds, is shown to explain all puzzling experimental facts on the d–d transitions of the studied systems and is of interest in the search of new Cu2+ and Ag2+ superconducting materials where a strong correlation between Δ and the transition temperature, Tc, has been conjectured.
AB - It is widely assumed that the gap, Δ, between dx2–y2 and d3z2–r2 orbitals in fluorides and oxides containing tetragonal Cu2+ or Ag2+ complexes directly reflects the tetragonal distortion in the MX6 complex (M = d9 ion; X = F–, O2–). This assumption on that relevant quantity is shown to be not correct through the study of pure K2CuF4-, KCuF3-, and Cu2+-doped KZnF3 and K2ZnF4 model compounds. Indeed, ab initio calculations prove that Δ in these insulating materials also depends on the internal electric field created by the rest of lattice ions on active electrons confined in a given CuF64– complex. This internal field, especially important for layered compounds, is shown to explain all puzzling experimental facts on the d–d transitions of the studied systems and is of interest in the search of new Cu2+ and Ag2+ superconducting materials where a strong correlation between Δ and the transition temperature, Tc, has been conjectured.
U2 - 10.1021/jz401227x
DO - 10.1021/jz401227x
M3 - Journal article
VL - 4
SP - 2385
EP - 2390
JO - The Journal of Physical Chemistry Letters
JF - The Journal of Physical Chemistry Letters
SN - 1948-7185
ER -