The modulated structure and ferromagnetic insulating state in a nine-layer BaRuO₃

We report the observation of a modulated structure and a ferromagnetic insulating state in a high quality single crystal of a nine-layer BaRuO ₃. Using x-ray scattering, the modulated satellites were observed to double the unit cell along the c-axis at low temperature. The ferromagnetic insulating state is confirmed by magnetic and resistivity measurements. Analyzing the peak profiles from the modulation and host structure respectively, showed a lattice distortion at T∼55K. These findings elucidate the intimate relationship between ferromagnetism and lattice distortion in a nine-layer BaRuO₃.