Reflectivity and Electronic Structures of Layered Ionic Crystals, (CnH2n+1NH3)2CdCl4: n=1, 2, 3
15 Jul 1989-Journal of the Physical Society of Japan (The Physical Society of Japan)-Vol. 58, Iss: 7, pp 2276-2279
TL;DR: In this article, the reflection spectra of (C n H 2 n +1 NH 3 ) 2 CdCl 4 were measured in the photon energy region of 0.5-25 eV at room temperature (RT) and liquid nitrogen temperature (LNT) by means of synchrotron radiation.
Abstract: The reflection spectra of (C n H 2 n +1 NH 3 ) 2 CdCl 4 were measured in the photon energy region of 0.5–25 eV at room temperature (RT) and liquid nitrogen temperature (LNT) by means of synchrotron radiation. It was found that absorption spectra of the present crystals resemble that of CdCl 2 crystals except for an additional peak at 5.10 eV (RT). The energy of the additional peak shifts with temperature by as much as 0.38 eV from 5.10 eV (RT) to 5.48 eV (LNT). This absorption peak has doublet structure and the splitting energy is 0.1 eV, which is the same magnitude as the spinorbit splitting of a chlorine atom. The band is assigned to be an electronic transition from the chlorine 3 p valence band to a new-type conduction band which is composed of alkylammonium bases and is below the ordinary Cd 5 s conduction band in energy.
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References
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TL;DR: In this paper, the authors measured reflection, luminescence and absorption spectra in an exciton region of (C 10 H 21 NH 3 ) 2 PbI 4, which is determined to be of layered perovskite type by X-ray diffraction.
355 citations
TL;DR: In this paper, the structure of the complex salt (C2H5NH3)2CuCl4 has been determined by conventional X-ray diffraction techniques, and a square planar CuCl42− ion was found with CuCl distances of 2.28 A.
119 citations
TL;DR: In this article, a microscopic model for the phase transition to a tetragonal phase is proposed, and two low temperature phase transitions are detected by means of DTA at about 283 and 173 K.
Abstract: (CH3NH3)2CdCl4 is found to be isotructural at room temperature with (CH3NH3)2MnCl4 having the orthorhombic space group Cmca. A high temperature phase transition to a tetragonal phase could not be observed because of a decomposition slightly above 383 K. Two low temperature phase transitions are detected by means of DTA at about 283 and 173 K. The first one leads to the space group P42/ncm. A microscopic model for this phase transition is proposed.
Fur die Raumtemperaturphase von (CH3NH3)2CdCl4 wird die mit (CH3NH3)2MnCl4 isostrukturelle, orthorhombische Raumgruppe Cmca gefunden. Eine Hochtemperaturumwandlung in eine tetragonale Phase konnte wegen thermischer Zersetzung oberhalb von 383 K nicht beobachtet werden. Mittels DTA werden zwei Tieftemperatur-Phasenumwandlungen bei ungefahr 283 und 173 K gefunden. Die erstere fuhrt zu einer tetragonalen Modifikation mit der Raumgruppe P42/ncm. Ein mikroskopisches Modell dieser Phasenumwandlung wird vorgeschlagen.
103 citations
TL;DR: The perovskite-type layer structure compound (CH3NH3)2CdCl4 exhibits an unusual phase sequence: the phase transitions are governed by changes both in the motion of CH 3NH3 groups and the hydrogen bonding scheme.
Abstract: The perovskite-type layer structure compound (CH3NH3)2CdCl4 exhibits an unusual phase sequence:
The phase transitions are governed by changes both in the motion of CH3NH3 groups and the hydrogen bonding scheme. Structural data are given for the tetragonal high-temperature and the monoclinic low-temperature phase. The whole phase sequence is discussed in detail.
Die perowskitartige Schichtstruktur-Verbindung (CH3NH3)2CdCl4 zeigt eine ungewohnliche Phasenfolge:
Die Phasenumwandlungen werden durch Anderungen sowohl im Bewegungsverhalten der CH3NH3-Gruppen als auch im Wasserstoff-Bindungsschema bewirkt. Fur die tetragonale Hochtemperaturphase und die monokline Tieftemperaturphase werden die Strukturdaten bestimmt. Zusammenfassend wird die komplette Phasenfolge analysiert.
97 citations
TL;DR: The intercalation-deintercalation process of weak interaction organic molecules such as 1-chloronaphthalene and o-dichlorobenzene into highly oriented polycrystalline (C10H21NH3)2CdCl4 films and he...
Abstract: The intercalation-deintercalation process of weak interaction organic molecules such as 1-chloronaphthalene and o-dichlorobenzene into highly oriented polycrystalline (C10H21NH3)2CdCl4 films and he...
74 citations