Journal: Journal of the American Chemical Society

Article Title: Universal Dynamics of Molecular Reorientation in Hybrid Lead Iodide Perovskites.

doi: 10.1021/jacs.7b09536

Figure Lengend Snippet: Figure 1. (a,b) Solid state 1H NMR (10 kHz MAS) spectra of perovskite FAPbI3 at temperatures near ambient. Asterisks indicate spinning sidebands. (c) Chemical shift and (d) peak width (full width at half-maximum, fwhm) when the data are fit with a single pseudo- Voigt function. (e) Spin−lattice relaxation time (T1) from inversion recovery experiments. The α−β phase transition is indicated. For (c− e), lines are to guide the eye only, and error bars are smaller than the markers and are omitted for clarity.

Article Snippet: Solid state 1H NMR experiments and T1 relaxation measurements under MAS near ambient temperature were conducted on a 500 MHz (11.7 T) Bruker Avance NMR spectrometer with a Bruker 4 mm H/ X/Y triple resonance MAS probe.

Techniques: Sublimation

Journal: Journal of the American Chemical Society

Article Title: Universal Dynamics of Molecular Reorientation in Hybrid Lead Iodide Perovskites.

doi: 10.1021/jacs.7b09536

Figure Lengend Snippet: Figure 2. (a) Solid state 1H NMR spectra of perovskite FAPbI3 at selected cryogenic temperatures. (b) Real permittivity (ϵr′) and (c) loss tangent (tan δ) from AC capacitance measurements. (d) Heat capacity (Cp) in the vicinity of the freezing of the molecular dipole from rapid warming (blue) and cooling (orange) sweeps, with prior measure- ments at fixed temperatures from the literature for comparison.14

Article Snippet: Solid state 1H NMR experiments and T1 relaxation measurements under MAS near ambient temperature were conducted on a 500 MHz (11.7 T) Bruker Avance NMR spectrometer with a Bruker 4 mm H/ X/Y triple resonance MAS probe.

Techniques: Comparison

Journal: Journal of the American Chemical Society

Article Title: Universal Dynamics of Molecular Reorientation in Hybrid Lead Iodide Perovskites.

doi: 10.1021/jacs.7b09536

Figure Lengend Snippet: Figure 5. Temperature-dependence of the molecular reorentation time (τrot) in FAPbI3 and MAPbI3 modeled from 1H T1 using the model of Bloembergen, Purcell, and Pound.72 Phase transition temperatures are indicated by solid (FAPbI3) and dashed (MAPbI3) arrows. Colored lines are to guide the eye only. (*) 1H T1 data for MAPbI3 are taken from Xu and co-workers.29 Reported reorientation times from GHz spectroscopy, quasi-elastic neutron scattering (QENS), ab initio molecular dynamics (MD), and 14N NMR are presented for comparison.15,16,23,24,36,42,73

Article Snippet: Solid state 1H NMR experiments and T1 relaxation measurements under MAS near ambient temperature were conducted on a 500 MHz (11.7 T) Bruker Avance NMR spectrometer with a Bruker 4 mm H/ X/Y triple resonance MAS probe.

Techniques: Sublimation, Spectroscopy, Comparison