Results of a search for monochromatic solar axions using 57Fe

We have searched for 14.4 keV monochromatic axions which could be emitted from 57Fe nuclei in the solar core. Using the resonant absorption of 57Fe nuclei, no evidence related to the axions is observed, and upper limit on axion mass of ma<216eV is obtained at 95% C.L. This limit is factor 3.4 more stringent than the previous similar experiment, and, except for the SN1987A arguments, the most stringent experimental limit purely obtained from axion-nucleon couplings.