Raman Spectra of the Half-Metallic Ferromagnet CrO2

Raman and infrared-active phonons in hexagonal HoMnO3single crystals: magnetic ordering effects

“…This mode effectively modulates Mn-O-Mn bond angles and, hence, the Mn-Mn exchange interaction. Similar phonon frequency anomalies near the magnetic ordering temperature have been reported earlier for CuO [16], SrRuO 3 [17] and CrO 2 [18,19].…”

Spin phonon coupling in rod-shaped half-metallic CrO2ultrafine particles: a magnetic Raman scattering study

“…It is seen that the room temperature ZF Raman scattering spectrum is mainly characterized by two peaks at 455.4 and 573.9 cm −1 , corresponding to the vibrational modes of E g and A 1g symmetries [17]. These two Ramanactive modes are internal phonon modes, involving only vibrations of the oxygen atoms which form the sublattice CrO 6 octahedron [17]. Upon applying a magnetic field, the Raman phonon (E g mode) parameters: frequency, intensity, and linewidth, show pronounced anomalies.…”

“…In particular, Raman scattering studies on the strong spin-phonon coupling, so-called polarons [15,16], have contributed significantly to the understanding of electronic transport properties in such MR materials. However, few Raman scattering studies have been carried out to investigate half-metallic CrO 2 [17,18]. CrO 2 is a metastable phase [19], and it can be decomposed into Cr 2 O 3 , which shows strong Raman peaks compared with CrO 2 , by a laser beam at a relatively low power [11].…”

“…Figure 2 shows the room temperature Raman spectra of half-metallic CrO 2 powder at ZF and at a low magnetic field up to 500 mT. It is seen that the room temperature ZF Raman scattering spectrum is mainly characterized by two peaks at 455.4 and 573.9 cm −1 , corresponding to the vibrational modes of E g and A 1g symmetries [17]. These two Ramanactive modes are internal phonon modes, involving only vibrations of the oxygen atoms which form the sublattice CrO 6 octahedron [17].…”

Chromium oxyselenide solid solutions from the atmospheric pressure chemical vapour deposition of chromyl chloride and diethylselenide

“…No evidence was seen for a secondary phase, such as CrO 2 or Cr 2 Se 3 . 33,34 Raman analysis of the delaminated black films revealed a weak, broad peak around 225 cm À1 (Fig. 7; quantification of relative peak heights between the Cr 2 O 3 and the Cr 2 Se 3 structure type patterns indicates ca.…”