Intertwined Magnetic Sub-Lattices in the Double Perovskite Compound LaSrNiReO6

Abstract

We report a muon spin rotation ($\hat{I}{¼}^{+}$SR) study of the magnetic properties of the double perovskite compound LaSrNiReO${}_6$. Using the unique length and time scales of the $\hat{I}{¼}^{+}$SR technique, we successfully clarify the magnetic ground state of LaSrNiReO${}_6$, which was previously deemed as a spin glass state. Instead, our $\hat{I}{¼}^{+}$SR results point towards a long-range dynamically ordered ground state below $T_{\mathrm{C}}=23$ K, for which a static limit is foreseen at $T=0$. Furthermore, between 23 K$<T\le$300 K, three different magnetic phases are identified: a dense ($23$ K$<T\le 75$ K), a dilute ($75$ K$<T\le 250$ K), and a paramagnetic ($T>250$ K) state. Our results reveal how two separate, yet intertwined magnetic lattices interact within the unique double perovskite structure and the importance of using complementary experimental techniques to obtain a complete understanding of the microscopic magnetic properties of complex materials.

11 pages (with references), 11 figures