We request four days of beam time to conduct zero and longitudinal field measurements on iridate pyrochlores A2Ir2O7 (A = Y, Lu, Nd) in the temperature range 200 K to 2 K and in fields from 0 to 0.1 T. Recent calculations predict that the combination of spin-orbit coupling and electronic correlations (tunable via choice of A) may produce ground state properties including a ¿4 in/4 out¿ Ir moment ordering on the geometrically frustrated tetrahedral sites and, for the A = Y compound, an unusual ¿Dirac semi-metal¿ phase. Samples are being fabricated at Boston College, with polycrystalline single-phase Y2Ir2O7 in hand; Nd and Lu variations are currently being fabricated. Proposals to perform complementary neutron scattering experiments are now being submitted by my collaborator Prof. Stephen Wilson of Boston College.