Mn12-acetate and related single-molecule magnets are promising candidates for high-density magnetic storage devices, spintronics components and even quantum computing applications. However, certain aspects of their fundamental properties are still not completely understood. The importance of spin-vibron interactions in the calculation of the magnetic anisotropy of Mn12-acetate was proposed a few years ago [1]. Some experimental evidence has already been given [2]. We present further evidence in support of this theory. A detailed Raman scattering study was performed by measuring polarization-dependent spectra in the 35-1500cm-1 frequency region, temperature range of 6-300K and in magnetic fields of up to 9T. A symmetry analysis of the vibrational modes revealed the presence of acetic acid disorder-related isomers with C1 symmetry. This confirms an earlier low-temperature X-ray study [3]. The observed temperature dependence of the vibrational modes was interpreted in terms of spin-vibron interactions. The influence of an external magnetic field on Raman spectra will also be discussed.

[1] M. Pederson et al., Phys. Rev. Lett. 89, 097202 (2002) [2] A.B. Shushkov et al., Phys. Rev. B 66, 144430 (2002) [3] Cornia et al., Acta Crystallogr., Sect. C: Cryst. Struct. Commun., 58, 371 (2002)