Cruz, C. R. Dela, Lorenz, B., Sun, Y. Y., Wang, Y., Park, S., Cheong, S-W., ...
Measurements of ferroelectric polarization and dielectric constant were done on $R$Mn$_2$O$_5$ ($R$=Tb, Dy, and Ho) with applied hydrostatic pressures of up to 18 kbar. At ambient pressure,...
Cruz, C. R. Dela, Yen, F., Lorenz, B., Gospodinov, M. M., Chu, C. W., Ratcliff, W., ...
Strong anomalies of the thermal expansion coefficients at the magnetic and ferroelectric transitions have been detected in multiferroic $RMn_2O_5$. Their correlation with anomalies of the specific...
Distortion-Dependent Raman Spectra and Mode Mixing in RMnO3 Perovskites (2005)
Iliev, M. N., Abrashev, M. V., Laverdiere, J., Jandl, S., Gospodinov, M. M., Wang, Y. -Q., ...
The polarized Raman spectra of orthorhombic RMnO3 series (R=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Y) were studied at room temperature. The variation of phonon frequencies with R ionic radius rR as a whole...
Low temperature dielectric anomalies in HoMnO_3: The complex phase diagram (2005)
Yen, F., Cruz, C. R. Dela, Lorenz, B., Sun, Y. Y., Wang, Y. Q., Gospodinov, M. M., ...
The dielectric constant of multiferroic hexagonal HoMnO_3 exhibits an unprecedented diversity of anomalies at low temperatures (1.8 K< T
Cruz, C. Dela, Yen, F., Lorenz, B., Wang, Y. Q., Sun, Y. Y., Gospodinov, M. M., ...
Evidence for a strong spin-lattice coupling in multiferroic HoMnO_3 is derived from thermal expansion measurements along a- and c-axis. The magnetoelastic effect results in sizable anomalies of the...
Novel Field-Induced Phases in HoMnO3 at Low Temperatures (2004)
Lorenz, B., Yen, F., Gospodinov, M. M., Chu, C. W.
The novel field-induced re-entrant phase in multiferroic hexagonal HoMnO3 is investigated to lower temperatures by dc magnetization, ac susceptibility, and specific heat measurements at various...
Litvinchuk, A. P., Iliev, M. N., Popov, V. N., Gospodinov, M. M.
Polarized Raman scattering and infrared reflection spectra of hexagonal HoMnO$_3$ single crystals in the temperature range 10-300 K are reported. Group-theoretical analysis is performed and...
A Field-Induced Re-Entrant Novel Phase and A Ferroelectric-Magnetic Order Coupling in HoMnO3 (2003)
Lorenz, B., Litvinchuk, A. P., Gospodinov, M. M., Chu, C. W.
A re-entrant novel phase has been observed in the hexagonal ferroelectric HoMnO3 in the presence of magnetic fields, in the temperature ranges defined by the plateau of the dielectric constant...