Quantum spin effects and magnetic short-range order above the Curie temperature
| Title | Quantum spin effects and magnetic short-range order above the Curie temperature |
| Publication Type | Journal Article |
| Year of Publication | 2009 |
| Authors | Gu RY, Antropov VP |
| Journal Title | Physical Review B |
| Volume | 80 |
| Pages | 214405 |
| Date Published | 12/01 |
| ISBN Number | 1098-0121 |
| Accession Number | ISI:000273228200050 |
| Keywords | ', 2-dimensional heisenberg-model, bcc iron, curie temperature, d, ferromagnetic materials, green, green-function theory, heisenberg model, iron, itinerant ferromagnetism, local-band theory, s function methods, short-range order, spin dynamics, spin waves |
| Abstract | Using the quantum Heisenberg model calculations with the Green's function technique generalized for arbitrary spins, we found that for a system of small spins, the quantum spin effects induce the additional magnetic short-range order and strongly affect physical properties of magnets. For instance, the spin waves in the present consideration can appear as a result of short-range spin fluctuations and do not require long-range magnetic order. Our spin dynamics investigation even indicates that these quantum spin effects favor the persistence of propagating spin-wave-like excitations above the Curie temperature. These model studies are relevant to itinerant magnets and suggest the increasing influence of quantum spin effects on the magnetic short-range order with a decrease in quantum spin value. The modified expression for the Curie temperature in ferromagnets is obtained. |
| URL | <Go to ISI>://000273228200050 |
| DOI | 10.1103/Physrevb.80.214405 |
