We report the synthesis and characterization of semipolar (11 (2) over bar2) oriented Al1-xInxN alloys over a wide composition range (0 <= x <= 0.55) using metalorganic vapour phase epitaxy (MOVPE) in a close coupled showerhead reactor system. AlInN layers were deposited on AIN buffer layers on m-plane (1010) sapphire substrates using trimethylaluminium (TMAI), trimethylindium (TMIn), and ammonia (NH3) precursors and the alloy composition tuned by changing the growth temperature from 860 degrees C to 625 degrees C, corresponding to an indium content from 2.9% to 54.6%. High resolution X-ray diffraction (HRXRD) measurements were used to determine the microstructure and anisotropic biaxial strain arising from the intrinsic tricilinic distortion of the unit cell in semipolar nitrides. The epilayers exhibit an overall tilt about the [1 (2) over bar 00] direction and phase separation was observed for samples with indium content over 40%. The ternary alloy compositions evaluated from HRXRD were compared with those obtained from optical transmission measurements. (C) 2014 Elsevier B.V. All rights reserved.