Microscopic Ferromagnetic and Antiferromagnetic Clusters in Pr${0.7}$Ca$_{0.3}$MnO$_{3}$

``Colossal'' magnetorestive manganite Pr$_{0.7}$Ca$_{0.3}$MnO$_{3}$ (PCMO30) is an ideal system to test the microscopic phase separation scenario because it has an inhomogeneous low-temperature insulating metastable state where ferromagnetic (FM), antiferromagnetic (AF), and charge/orbital (CO-OO) phases coexist. On cooling from room temperature, a CO-OO state occurs below T$_{CO-OO }\sim $200 K, followed by AF ordering below T$_{N }\sim $140 K. Below T$_{C }\sim $110 K, the magnetic structure develops a FM component coexisting with AF ordering. We have used neutron scattering to study FM, AF and CO-OO phase transitions in a single-crystal PCMO30. The diffuse scattering of FM component demonstrates the presence of short-range ferromagnetic clusters both above and below T$_{C}$, while no diffuse component in the CO-OO scattering peaks has been observed near T$_{CO-OO}$. Interestingly, the short-range AF correlations associated with Mn$^{4+}$ sites but not with Mn$^{3+}$ sites are observed for both above and below T$_{N}$, indicating that the local AFM clustering is directly associated with doped holes in this system. The work was supported by NSF-DMR0453804, NSF-DMR0346826, DE-FG02-05ER46202, and DOE DE-FG02-04ER46125. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725.