Raman scattering investigation of cesium plumbochloride, CsPbCl₃, phase transitions

Abstract

We report a Raman scattering investigation of CsPbCl 3 as a function of temperature in four different scattering configurations allowing us to obtain the various irreducible representations of the appropriate symmetry groups describing the substance in its successive phase transitions: cubic, tetragonal, orthorhombic and monoclinic or orthorhombic. We identify the correct 'parentage' of the observed modes with respect to infrared reflectivity data reported in the literature in accord with the Lyddane-Sachs-Teller relation, which was not fulfilled in previous assignments. We demonstrate the presence of strong correlation chains, which maintain the compound in a pseudo-cubic state as far as x-ray, infrared and Raman spectroscopy are concerned. The intensity of the related central peak was analysed on the basis of a Debye-type relaxation as a function of temperature; the results show perfect correspondence of its variations and the temperatures of the phase transitions. In addition, an order-disorder phase transition is evidenced at low temperature, 193 K (−80 • C).

Coherent phonon oscillations in CsPbCl 3 nanocrystals

“…The obtained values are given in Table 1, which contains also the frequencies of phonon modes measured by conventional Raman scattering in bulk CsPbCl 3 (Ref. [6]). All observed phonon modes can be matched well to the bulk CsPbCl 3 frequencies (optical phonon frequencies of CsCl are considerably higher -TO: 106 cm -1 , LO: 163 cm -1 [10].)…”

“…Cesium leadchloride (CsPbCl 3 ) is rather untypical semiconductor [5], however, the investigation of this material has been motivated mainly by its possible application as a scintilator or an ionic conductor [6,7]. It has the perovskite type structure with a rich phonon spectrum, which has been studied theoretically and experimentally [6,7]. Recently, the preparation and properties of CsPbCl 3 nanocrystals in CsCl host matrix were reported [8].…”

“…The coherent phonons have been studied in a variety of bulk semiconductors [1,2], recently also some reports on semiconductor nanocrystals appeared [4]. Cesium leadchloride (CsPbCl 3 ) is rather untypical semiconductor [5], however, the investigation of this material has been motivated mainly by its possible application as a scintilator or an ionic conductor [6,7]. It has the perovskite type structure with a rich phonon spectrum, which has been studied theoretically and experimentally [6,7].…”

From soft harmonic phonons to fast relaxational dynamics inCH3NH3PbBr3

“…The result is also consistent with previous work on the phase transitions CsPbCl 3 which were found to result from soft tilt modes of the PbCl 6 octahedra. [19,[31][32][33][34] The more intense, higher-energy modes that disappear at T c are related to H motion. CH 3 NH 3 PbBr 3 therefore represents a case where a displacive PbBr 6 octahedra transition is coupled to an order-disorder MA transition, corresponding to melting of the orientational order.…”

Dynamics of coherent phonons in CsPbCl3 nanocrystals studied by femtosecond laser spectroscopy

“…1a (points). As we described in detail previously [4,5], numerical Fourier analysis of the oscillations reveals that they are formed by four distinct oscillation modes which can be attributed very well to the lowest confined phonon modes derived from four optical phonon modes of the bulk CsPbCl 3 observed independently by the standard Raman spectroscopy [8]. At low temperatures bulk CsPbCl 3 is in the so-called phase IV which is orthorhombic (D ) and has a rich spectrum of the phonon modes [9].…”