Magnetic properties of FeSn(OH)6 and its oxidation product, FeSnO(OH)5

Fe2+Sn4+(OH)6 is oxidized in air. As the oxidation product, new compound Fe3+Sn4+O(OH)5 was confirmed. Fe3+Sn4+O(OH)5 has a same structure as that of FeSn(OH)6. Magnetic properties of these two compounds are investigated; FeSn(OH)6 is paramagnetic down to 1.4 K, FeSnO(OH)5 shows an antiferromagnetic order around at 4.2 K.