Related Experiment Video
Updated: Jun 5, 2025

Electron Channeling Contrast Imaging for Rapid III-V Heteroepitaxial Characterization
Published on: July 17, 2015
Boson-Peak-Like Anomaly Induced by Dipole Disordered States in (CH_{3}NH_{3})_{4}InCl_{7}
Zhaolong Liu1,2, Rui Luo3, Munan Hao1,2
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, <a href="https://ror.org/05cvf7v30">Chinese Academy of Sciences</a>, Beijing 100190, China.
Abstract:
Boson peaks are observed in glassy materials due to atom, spin, and strain disordered states that provide additional vibration modes at low temperatures. However, Boson peaks have not been observed in pure dipole disordered systems without structural disorder. Here, we report the observation of a Boson-peak-like hump in specific heat near 7 K in organic-inorganic hybrid crystal MA_{4}InCl_{7}(MA=CH_{3}NH_{3}). The energy barrier for unbonded Cl anions migration is extremely low, allowing that the migration persists down to low temperatures. The migration and the subsequent relaxation process induce a random change in its dipole, leading to the dipole disorder states. Our results show that MA_{4}InCl_{7} can be regarded as a dipole glass that can give rise to the Boson peak as well.
Related Concept Videos
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Hybridization of Atomic Orbitals I
NMR Spectroscopy of Benzene Derivatives
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
π Electron Effects on Chemical Shift: Overview
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...

